1: View with gates OPEN
View with gates CLOSED
Post with Control Boxes
the mechanisms of
gate openers were in excellent shape (even after 17 years of service!),
it seemed a shame to spend $3800 plus installation to replace the two
heavy duty gate operators.
So.. Since I am a circuit designer by education and
Building Automation Engineer by recent experience, I set about to "fix
it". I already had a programmable Automation Controller at my
gate to activate the EDKO motor units as well as for other purposes.
I decided that the best (and most economical approach) was to
just design a relay interlock unit for the EDKO motor units (to prevent
the Automation Controller from ever commanding the motors to run both ways at
once) and then program the existing Automation Controller to do all the logic
operations involved with operation of the gate. As you read the
article, you will discover that this new Gate Operator
Controller has dramatically increased
features as compared with any Gate Operator on the market.
The entire design is described below. Using this design,
the upgrade/repair cost was
dramatically less than replacement. The design, prototyping of
two Relay Modules, rewiring, and then programming /debugging the UUC8
Automation Controller program took just 4 days total. I figure a
day or two would be enough to replicate my effort on another dual gate
system now that the design is complete.
Installation for a single gate system might take a day.
In the above Figures
1 &2 the finished product is shown. Figure 3 shows
control boxes located on the gate post. The upper box
the vehicle loop sensors along with the Chamberlain Garage Door Radio
Receiver used for remote control unlocking should the gate be closed
when a user approaches the locked gate at night. The upper
also mounts the OPEN/CLOSE/STOP manual push button
assembly. To the right, mounted on the fence, is the (optional
for others) Davis Rain Guage which is also connected to the Automation
Controller which transmits the data to the central controller in the
house for display. The lower junction box contains the HI
Solutions UUC8 Automation Controller which is used as the logic
controller for the two gates and for other related control features
described below. I can furnish parts for replicating this
installation OR you can "do your own thing". The UUC8 is
ideal for this control functionality, operates in the gasketed plastic
junction box from about -10F to 140F, and its inputs and outputs
all include voltage transient protection. Even so, if you
or output wires from the UUC8 board more than maybe 20ft from the
controller in an outdoor environment, a 100vac transorb transient
snubber is HIGHLY recommended on any I/O wire going more than maybe
20ft away from the UUC8.
On short runs such as between gateposts, I have not had a
problem. A transient suppressor on the
120vac power line is required for long term security of the AC power
source. You could use some other "programmable controller"
instead of the UUC8 but make SURE it has transient protection and is
rated for outside environments so it can survive in the cold/hot of the
out-of-doors. Boards that are not conformal coated and otherwise
protected do not last long in harsh environments.
Features included in the new system design
Features are optional on any particular installation. ****
Features may require simple program modification.
1) The new design includes a replacement circuit board for the old EDKO
(or other brand) board inside each Gate Operator.
2) The new design removes the old (if any) obstruction module and 24vac
transformer in the Gate Operator housing.
3) The new design uses the old OPEN LIMIT, CLOSED LIMIT , and
OBSTRUCTION (all SPDT) microswitches in the EDKO or other Gate Operator unit.
4) Provision is made for manual OPEN/CLOSE/STOP
switch inputs for local gate control.
Provision is made for an outside vehicle loop sensor plus
inside loop sensor in case you want separate logic for the two cases to detect direction of travel for vehicles.
OR: You can use one vehicle loop sensor input for
if you want to do the same operation sequence independent of a vehicle coming or going.
Provision is included for a daily schedule of
OPEN/CLOSED times if desired. If you wish NOT to use a day/night schedule, a lock out strap is required.
UUC8 internal clock loses/gains about one minute a month. About
once a year, you will need to connect a PC to the controller and set
the correct time.
Provision is made for disable of the
VEHICLE SENSOR(s) so as to just use a single contact closure from a Garage
Door Radio Receiver to open or close (toggle) the gate.
Provision is made for a 24vac triac output to drive a relay to
on Post Lights when a vehicle arrives at the gate and is sensed by the
vehicle loop sensor.
Provision is made for a 24vac triac output from
the Automation Controller (plus a transmission to the Central
Controller if equipped) to signal for turning on of other outside lighting
when a vehicle arrives at the gate going in the direction of the house.
Provision is made to accept toggling
switch outputs from a Davis Rain Guage and to totalize the rainfall information
and send it to the Central Controller (if equipped).
is made to accept a contact closure (MSEN) (from a mailbox mounted
switch or Visonic Transmitter/Receiver) to signal mailbox door opening
and status. This is used in conjunction with vehicle loop detection to
provide information that a) The mail has arrived today (gatepost light
turns ON when mail has arrived and then vehicle sits on sensor loop) and b) Mail has been picked
up already today or has not arrived today (gatepost light does not turn ON when
vehicle sits on loop in these cases.) This has proved very handy over the
years! If a Central Controller is attached, the mail's
also signaled to the house.
Note: If you DON'T want to use
the optional features noted **
, then you simply do not make connections
to those inputs/outputs on the automation controller and these features
are automatically inoperative. There are no programming
needed to disable these optional features! And no software to add if you WANT them!
Now to the circuit
designs. I am a circuit designer who believes in LONG LIFE
designs. This design uses 40amp encapsulated solid state
relays instead of the 10amp Triacs as in the original EDKO
design. Everything else is voltage and power derated by 50% or
more to insure long life. The schematic of the module I designed
for the replacement of the
circuity board and obstruction modules in existing EDKO SSL, SSW, and
MSW units is shown below. Holes in the actual board allow
to mount on the same plastic standoff supports as used for the SSL,
SSW, and MSW
boards which I had. About other models, I do not have
information. As to applicability of this design for a specific
Gate/Door Operator system, you can examine the wiring
diagram for your model unit (or email the wiring diagram to me) to check for:
a) a SPDT microswitch for sensing when the gate is OPEN,
Another SPDT microswitch for sensing when the gate is CLOSED and c) Probably a
third SPDT microswitch sensing when the gate has struck an obstruction.
d) The motor drive needs to be as shown in figure 4 below with a
common neutral and motor drives right or left depending on which side
of the split capacitor motor winding is fed with AC power. IF
your Gate Operator has all these features, then it should be capable of
"updated" to use the controller design included in this document.
The circuit diagram for the replacement module in the EDKO
Operator and ALL of the associated wiring INSIDE of the Gate Operator cabinet is shown
below in figure 4.
Circuit of Printed Circuit Board (top) and rewired limit
Photo of finished Replacement
(With holes to mount on
existing standoff posts)
Figure 4 Note: JPG image of figure 4 can be viewed HERE
I have had several inquiries about the possibility of making a
PWB that could DIRECTLY replace the old EDKO board. Frankly, I do
not like the negative voltage logic used in the old EDKO design, but it
would be quite easy to add a few parts and design a circuit board to
replace the old board using modern CMOS positive logic components.
I could produce ten such boards to sell for about $80 each IF
there was sufficient interest. I note that most people seem happy
to just replace their EDKO gate control units with new. Anybody
got an old EDKO SSW or MSW gearbox/motor unit they want to get rid of?
I would like to have a spare mechanical assembly.
Relay Module and Limit Switch Operating
Descriptions for EDKO Operators:
7-pin connector shown at the bottom of the
uses 7 pins of the EXISTING "outside world" terminal strip inside the EDKO
SSL/SSW/MSW or other Gate Operator. Note Carefully: The
Gate Operator Motor Unit is rewired completely to
connect as shown above in figure 4. Leave NO OLD WIRING deviating
from the above drawing in place. Pin 1 is
Common Ground, Pin 2 is
STOP SWITCH input, Pin 3 is the OBStruction Switch output
(switch closes momentarily to GND on gate hitting obstruction), pin 4 is the CLOSED
LIMIT switch output (pin 4 is connected to GND when gate fully CLOSED), pin 5 is
24vac (or DC) OPEN COMMAND signal to the gate relay module, Pin 6 is
24vac (or DC) CLOSE COMMAND to the gate relay module and Pin 7 is the OPEN
LIMIT switch output (pin 7 closed to GND when gate fully OPEN). Note:
A seven conductor cable from the Gate Operator to the
Controller is required..
The relay module circuity is designed so that
it is not possible to command the OPEN and CLOSE relays at the same time which
could cause a fuse to blow or even motor failure. .
wiring error or other malfunction should erroneously command OPEN and
CLOSE at the same time, the CLOSE command will not be allowed and the
OPEN command will take precedence. Note: NEVER swap input
(open to the closed terminal and vice versa) wires on the Relay
module connector to obtain opposite motor directions as this will cause
the limit stops to work improperly.. Wire it just like the drawing.Gate Operator Notes:
Although a 15amp AC line fuse was shown on my SSW/MSW wiring diagrams,
no such fuse was found in the Gate Operator itself.
2) The Gate Operator Motors must
must be wired differently depending on if the Gate Operator
the LEFT side of the gate or on the RIGHT side of the gate.
This applies to both single and dual gate operator systems. Since
I can never remember which way is which, here is how you test.
BEFORE you connect up the wires to the 3 pin motor connector,
Turn the AC Power toggle switch in the gate operator to OFF,
Connect up the neutral wire to the WHITE wire from the AC power source.
then temporarily connect the BLACK wire going to the Gate
Motor to the BLACK wire coming from the AC Power source.
MAKING SURE you are not about to be hurt by the gate or actuator
arm!!!, JUST MOMENTARILY flip the AC power toggle switch to
then IMMEDIATELY back to OFF. The gate actuator arm will "lurch"
way or the other. c) Decide if the "lurch" was in the OPEN or
CLOSED direction. Then the BLACK wire going into the motor is to be
direction" (ie: OPEN or CLOSE) and connected either to pin #1 (OPEN
direction) or pin #3 (CLOSE
direction) as appropriate on the 3 pin connector going to the Relay Module. For a system with two gate
the BLACK "should" be the opposite on the "other" side.
recommend testing to be sure! The (on my unit) PINK wire from the
motor should be labeled the "other" direction and so connected to the appropriate pin in the 3
pin motor connector going to the Relay Module. Testing the Relay Module after it is installed into the Gate Operator and wired
you install the Relay Module and wire up all the limit switches and in
fact, complete ALL the wiring inside the Gate Operator-- Check every
wire! for correct connection on both ends. When you are satisfied
that the wiring is right, and power is available at the EDKO
unit, proceed as follows BEFORE you connect the EDKO to the UUC8
1) In every case, BE SURE that IF the motor moves when it should not, YOU and your TOOLS are out of harm's way!
2) Start with the Gate Operator AC power switch turned OFF.
Both pin 1 (OPEN) and pin 2 (CLOSE) of the Relay module (Pin 5
and Pin 6 on the rewired EDKO terminal strip)should be at ZERO
volts AC or DC.
Use your ohmmeter to verify that at least ONE (OR BOTH) of
Relay Module Pins 3&4, Pin 3 (goes to the OPEN limit switch)
or Pin 4 (goes to CLOSED limit switch) is in the CLOSED (zero
ohms to the GND pin) position. Note that if you have it
wired right and the operator has driven to the OPEN position, then the
OPEN LIMIT switch (on Relay Module pin 3) should be OPEN.
Conversely, if the gate
operator has been driven to the CLOSED position, then the CLOSED LIMIT
switch (on Relay Module pin 4) should be OPEN. In between the
limits BOTH switches will
be closed and both of pin 3 and pin 4 on the Relay Module
be CLOSED to GND when tested with an ohmmeter.
5) Then MOMENTARILY
turn the AC Switch to ON then immediately back to OFF.. The Gate
Operator SHOULD NOT move. If it does check the voltages and
wiring on the Relay Module OPEN and CLOSE inputs. No voltages should be present on these terminals.
6) In the following steps, be
prepared to jerk the 12vdc or 24vac power off the terminal if the motor
runs the wrong way, moves beyond where the close or open STOP limit
should be or something else happens that is unexpected!! Be
For this test, the STOP input (Pin 2 on the EDKO main terminal
strip) should be connected to GND (pin 1 of the same strip) if it is
not already connected through the STOP switch as shown in the system
wiring diagram. Now take a 12vdc battery (or a 24vac transformer
and ground the battery negative (or one side of the 24vac) to the EDKO
Terminal Strip Pin 1 BLACK (GND) terminal.
8) Then (Use care
now!) touch the 12vdc positive terminal (or the 24vac wire) to the OPEN
INPUT (EDKO Main Terminal Strip Pin 5). The Gate Operator should run to
the OPEN position and stop when the OPEN limit switch opens.
Adjust the OPEN Mechanical Limit nut per manual if needed. Take the 12vdc/24vac off Pin 5 when the gate stops.
While the operator arm is at the OPEN position, use your ohmmeter to
check from the EDKO Terminal Strip Pin 1 (BLACK=GND) to OPEN LIMIT
Terminal Strip Pin 7. You should read ~ zero ohms. Then
measure from GND to Pin 4 (ORANGE=CLOSED LIMIT). You should read
an open circuit.
10) Then touch the +12vdc (or 24vac) lead to the
CLOSE INPUT (EDKO Terminal strip Pin 6). The motor should run the
Gate Operator to the CLOSED position and stop. Adjust the CLOSED
Mechanical Limit nut per manual if needed.
11) While the operator is in the CLOSED position, use your ohmmeter to check from EDKO
Terminal Strip Pin 1 (BLACK=GND) to OPEN LIMIT Pin 7. You should
read an open circuit. Then move your ohmmeter probe to EDKO
Terminal Strip Pin 6 (CLOSED LIMIT). You should read ~zero ohms.
This completes the Gate Operator testing except for the
Obstruction Switch which we will test when we have the Automation
The HI Solutions UUC8 Unitary Automation Controller
The Automation Controller I used
is the model UUC-8 manufactured by HI Solutions, a well known Building
Automation manufacturing company in Georgia. They make
equipment for Cutler Hammer, Eaton, and other manufacturers.
They have their equipment installed in perhaps 10,000 large
buildings in the USA alone. Below is a photo of
the UUC-8 which I used as my "embedded controller" for the EDKO
Gate Operator system redesign. Other embedded controllers may be
found to be suitable as well.
Notes on UUC8 Pinouts and Pin Functionality for this application.
1) Important! The 5 pin "plug on" connectors used with the UUC8 are numbered
left to right 1,2,3,4,5. OFTEN these numbers have NO BEARING
on the pinout IDs used on the UUC8 board itself. Always use the pin
numbers printed on the circuit board! Refer to the MANUAL
for details or to the photograph above for UUC8 pinout functionality.
2) The AO (Analog Outputs) connector is shown on the lower left
Figure 5 isnot used in this design. The UI/AI
1 thru 8 are next in clockwise rotation on Figure 5 (we use several
AI/UI inputs as DIGITAL SWITCH INPUTS as shown in the following wiring
next connector in rotation is the connector for L-/L+ (where
the board is part of a ULAN NETWORK, then Ground and 24vac
power, Ground, Then there are the two DIGITAL OUTput
connectors. We use DO1 (pin 5) as OPEN1 command to the EDKO
Relay Module, DO2 (pin
4) as CLOSE1 to the same EDKO Relay Module, pin 3 (X) is 24vac
input, DO3 (pin 2)
is OPEN2 to the second EDKO Relay Module (if equipped), DO4 (pin
5) is CLOSE2 to the second EDKO Relay Module (if equipped).
for the second OUTPUT connector, DO5 (pin 5) is 24vac output
to an optional relay to turn on outside lights when the
Controller vehicle sensing loops sense an INCOMING VISITOR. A
relay can also be connected to the gatepost light output on
output DO6 if desired. This relay can be used to turn on a
gatepost light upon vehicle trip of one of the vehicle loop sensors or
when the radio signal unlocks the gate.
EDKO Operator to UUC8 Interconnect Wiring
The Interconnect wiring between the two EDKO Gate Operator units and
the rest of the system hardware including the UUC-8 Automation
Controller and other components such as a) manual
OPEN/CLOSE/STOP switch module, b) Inside vehicle sensor SOUT, c)
Outside vehicle Sensor NORT, and d) Mailbox Sensor Switch contacts
(MSEN) (if desired). The overall system interconnect wiring
follows. A PDF
image of this drawing is HERE
Figure 6 - System Interconnect wiring between the Relay Module(s) , UUC8 controller and the various sensors and control inputs.
Availability: By October 2010, I will have a finished printed
circuit board for the Relay Circuit Board shown in Figure 4. I
can furnish a Relay Module board including all parts and tested
for $80 each including USA shipping. I can also provide UUC8
controllers already programmed with the program detailed below or you
can buy the UUC8 directly from HI Solutions if you wish to buy the $160
programming adapter from HI Solutions and "program it yourself".
A single UUC8 will control ONE or TWO gates as needed without any
modifications. If needed, I will charge the cost of the card plus
$50 to program the card for you if you prefer a "ready to install"
package.. This would include
making the OPENING/CLOSING schedule to your needs if requested.
A UUC8 board comes
in several models. The lowest cost model UUC8-x24 is suitable for
this application and sells for about $400. The unprogrammed
board can be
purchased from HI Solutions, Kennesaw, Ga. OR> If you
want to "do it yourself" you can use any embedded controller with
suitable inputs and outputs and adapt the program as needed.
powerful Caveat: There are NO WARRANTIES OF ANY KIND provided
that this design and/or equipment will work in YOUR application.
That decision depends solely on YOUR expertise and judgement.
All the above modifications ARE straightforward
IF you know what you are doing! A good Electric Gate Operator
Technician should be able to get his first system changed out in
a day or two IF he clearly understands the wiring diagrams and
discussion contained herein. If you do not understand the
technical information provided, DON'T START THE WIRING or injury to
people and your
equipment could result!
. UUC8 Database for Controlling the Gate Operator(s) and Accessories
The OPERATING PROGRAM for the UUC8 to operate this system is found HERE.
As you can tell, the programming language is "sort of" like BASIC
programming for the MONITORS. And the Monitors and "Alarm" commands are "where the
action is". You can use these commands in the listing to
program your own UUC8 or I can provide a UUC8 already programmed with
this application program if you prefer.
In any event, hopefully this writeup and a day or so of hard work will give you success in getting your
broken EDKO back into service. The modification of each Gate
Operator took me about 4 hours and then rewiring the Automation
Controller box took me another 5 hours. The software program
debug time, I will not go into! :) Luckily, once software
is properly tested, it replicates nicely. So the conversion time
is not too long if you get all of your parts and tools together before
you start. It would be possible for me to get the UUC8 fitted
into a junction box with the necessary AC and low voltage wiring and
terminal strips so just hooking up seven wires from each Gate Operator
plus wires from outside accessories would be all that was required in
the field. But I suggest you do this yourself. It is really
pretty easy and straightforward and "doing it yourself" will insure
that you can fix it later.Overall System Checkout and Operation with Relay Module(s), Vehicle Loop, Radio Control, and Manual Push Button Inputs
of the completely wired system is pretty simple and requires maybe half
an hour. Don't skip any steps except for those testing features not
implemented in your particular installation. As is normal for
gate equipment, a periodic functional test of the gate and safety
features should be done to insure that all is well. The following
steps will test your entire control and motor drive system.
procedure assumes that you have successfully completed the tests under
the paragraph, "Testing the Relay Module" and that all tests were
successful. It is also assumed that all of the applicable wiring
shown above in Once the relay module test are completed, proceed as
2) Initially turn OFF the 120vac power to the Gate
Operator(s) so that the motors will not run while we do the initial
checks of the wiring and the UUC8 Automation Controller.
3) Plug in
UUC8 Power/ULAN connector (labeled L-/L+/GND/24v common/24vac) in Figure 5
above. Leave the other already wired connectors installed.
Now turn ON the 24vac to the UUC8. At this point, at
least one LED light should show on the UUC8, and you should
be able to measure 24vac from the 24vac Common connection on the power
transformer to both of the #3 pins on the DIGITAL OUTput connectors and to the 24vac pin on the Power/GND/ULAN connector.
You should measure ZERO volts AC on all of the DIGITAL OUTputs 1
Now turn the AC Power ON in each of your connected GATE OPERATORS.
The operators should NOT move, if they do something is
miswired. Assuming they do not move, plug the Digital
Output 1, 2, 3, 4 connector (with BRN/Yel/Brn/Yel wires in it), onto
the five pin DO1>DO4 header. The gate still should not move.
5) At this point momentarily push your MANUAL OPEN BUTTON and
AI/UI pin 5 should go to GND and 24vac should be found on DO1 and DO3
pins (OPEN SIGNAL) and the gates should go to the OPEN state and stop
automatically. The first and 3rd LEDs on the LED pack closest to
the DO connectors should turn ON while the gates are running and should
turn OFF immediately when the limit switches close and in not more than
20 seconds based on a timer. The first LED is closest to the UNITARY
CONTROLLER lettering on the card.
6) Check to insure that the STOP
signal from the OPEN LIMIT SWITCH#1 has grounded pin Digital
Input 1 (DI1) and if a second gate operator is equipped, also that the
OPEN LIMIT SWITCH #2 has grounded pin DI5. If the limit switch
inputs are NOT grounded, check your wiring from the limit switches to
the inputs. These will be the first and fifth LEDs
Now we test CLOSE operation. Momentarily press the MANUAL
CLOSE switch button. The gate(s) should close and come to a stop
at the closed limit stop position. This time, LEDs 2 and 4 on
the DO LED strip should come on and remain on while the gates are
moving and immediately go off at the end of travel if the CLOSE LIMIT
STOP signals are properly connected. When the gate comes to a
stop, check that Digital Input DI2 is grounded, that DI LED #2 is ON
and if you have a second gate, that also DI6 is grounded and that DI
LED#6 is ON. If this is correct, then you have completed the
limit stop and OPEN?CLOSE gate control tests.
8) The EDKO
gates have an OBStruction switch. If you start the gate to
CLOSEing and then hold the gate with moderate force to retard its
closing, you should hear a "CLICK" sound in the Gate Operator and the
gate(s) should IMMEDIATELY reverse and go to the OPEN position.
If you have two gates, run this test with both gates. The
OBStruction switches are momentary contact (Normally OPEN) so the DI
LEDs #3 and #7 barely "wink" on. If the obstruction stops do not
work, check by momentarily grounding DI input 3 or DI input 6 while the
gate is closing. The gate should stop and reopen immediately.
Assuming it does, check the OBStruction switches and wiring
against the drawings.
The Radio, Loop Sensors, MSEN, and other
switch wiring should be straightforward. When either of the LOOP
SENSOR inputs is grounded, the gates should open and stay open for 20
seconds following the vehicle clearance. If the gate is LOCKED by
the night schedule, a momentary contact on the RADIO input will UNLOCK
the gate for as long as the vehicle is on the loop sensor plus 20
8) If you want to use the "mail has arrived"
feature, request the test procedure for this special feature. The
program already is installed.
9) If you wish to NOT use the
scheduler to LOCK the gate, then you must GROUND pin AI/UI 4-1:17I and
the scheduler will be disabled.
9) If you want to use the Gatepost
night light feature, connect a 24VAC relay coil to DO5, ground the
other side of the coil and place the contacts in series with your
120vac light. The light will turn on when a car triggers
one of the loop sensors and the gate is closed, the light will come on
for the duration of the gate open sequence.
NOTE: I recently had an email from Bob Lanzarone Jr. at
BTI. He states that BTI has available most electrical and
mechanical parts needed for repair of EDKO equipment.
Please give me feedback if you order something from them. Joe
BTI ACCESS CONTROLS, Inc.
3516 E. Norvell Bryant Hwy
Hernando, FL 34442
I am sure I have left questions unanswered. Let me know your questions and I will add answers to the article.
Contact Joe Mehaffey
Answers to Questions posed by Readers:
1) Why did you not make the input voltage to the relay module be 0 and 5v?
In out-of-doors environments, I like 12 or 24 volt signaling as
a) it is inherently more noise resistant than 5v signalling, b) it is
inherently more immune to induction surges such as from lightning and
c) it is more tolerant to differences in common mode ground potentials
between equipment enclosures outside. The HIS UUC8 uses Triac
Outputs for robustness(and convenience in driving industrial controls)
and inputs are 12 or 24vdc voltage swing inputs for robustness
and noise immunity.
2) How is the Rain Gage information and the Gate Status displayed in your house?
See Image below. This information is displayed on a
wall mounted touchscreen display furnished by HI Solutions, Inc.
It also displays on any PC. (Image is 1/2 normal size). For
example, you can "touch" the "GATE LOCKED YES" Icon, then select UNLOCK
from the menu and the gate system will automatically UNLOCK.. The
Mail indicators tell you if the mail has arrived and if one of the
family has picked it up. Other displays show the rainfall today
and for the last 5 days. These features exist in the gate
operator described above, but require additional hardware in the home.
3) How do I wire the setup if I just have ONE EDKO Gate Operator Unit?
You simply run wires as shown for just ONE of the Motor Units
(say the West Gate Motor Unit) and then simply omit any wires that are
shown running to the EAST Gate Motor Unit. Then, when testing,
omit any reference to the "East Gate Motor Unit/East Relay
Module" and everything should work fine with just the one Relay Module
The program listing seems to show a lot of seemingly unnecessary
and redundant terms in the control equations. Have you optimized
Answer: Well.. There are some sneaky things
that can go on in any electromechanical system. For example,
it you were to "instantly" (or just too quickly) try to reverse
the gate by changing from OPEN to a CLOSE command while the gate was in
motion, it is very likely that the gate would continue to go to the
OPEN (or CLOSE) state despite the CLOSE relay being deactivated
followed immediately by the OPEN relay activation. This is a
characteristic of the motor design used in most gate operators.
I could have implemented a "brake" circuit to quickly stop the
motor and then reverse it, or I could (as done in this design) simply
wait a few seconds for the motor to stop before allowing the gate to
reverse. In other cases, I was just being perhaps overly
careful. It does not cost extra in a program design to be sure
when you want to STOP the gate to shut off both the OPEN and CLOSE
commands for both gates. Have I Optimized the program?
Perhaps not, but I have tested it extensively for functionality
of all features and safety in its operation. At this point, I
know of no remaining "bugs" in the design. But... No doubt SOMEBODY will find one!
Note: This redesign has been operating