midon design RS232Relay User manual

midon design
RS232Relay User Guide Version 3.02 Page 1 of 23
A Serial Relay Interface
RS232Relay
Figure 1 RS232Relay
RS232Relay User Guide Version 3.02
January 20, 2022

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RS232Relay User Guide Version 3.02 Page 2 of 23
1. Table of Contents
1. Table of Contents ..........................................................................................2
1.1. List of Tables..........................................................................................3
1.2. List of Figures.........................................................................................3
2. Introduction....................................................................................................4
3. Installation......................................................................................................5
4. Configuring RS232Relay ...............................................................................8
4.1. MOM.......................................................................................................8
4.2. RLT.........................................................................................................8
4.3. TYP.........................................................................................................9
4.4. SPR........................................................................................................9
4.5. CLO........................................................................................................9
4.6. DEB......................................................................................................10
5. Using RS232Relay ......................................................................................11
5.1. RLx.......................................................................................................11
5.2. RLS ......................................................................................................11
5.3. PLx .......................................................................................................11
5.4. DIS .......................................................................................................11
5.5. RLT.......................................................................................................12
5.6. TYP.......................................................................................................12
5.7. RTC......................................................................................................12
5.8. HLP ......................................................................................................13
5.9. MEM.....................................................................................................13
5.10. VER...................................................................................................13
5.11. ZZZ ...................................................................................................14
5.12. Input Timeout....................................................................................14
6. RS232Relay Command Summary...............................................................15
7. Software Change History.............................................................................17
8. Trouble-Shooting Problems with RS232Relay.............................................18
9. Error Messages ...........................................................................................19
10. RS232Relay Schematic ...........................................................................20
11. Legal Disclaimer.......................................................................................23

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RS232Relay User Guide Version 3.02 Page 3 of 23
1.1. List of Tables
Table 1 RS232 Cable Connections.......................................................................6
Table 2 RS232Relay Command List...................................................................15
Table 3 RS232Relay Software History................................................................17
Table 4 Common RS232Relay Problems and Resolutions.................................18
Table 5 RS232Relay Error Messages.................................................................19
1.2. List of Figures
Figure 1 RS232Relay............................................................................................1
Figure 2 Location of Connectors (Version C PCB)................................................5
Figure 3 Version D PCB........................................................................................6
Figure 4 Corrected Relay Contacts (Version C PCB ONLY).................................7
Figure 5 RS232Relay Schematic (Version C PCB).............................................20
Figure 6 RS232Relay Schematic (Version D PCB).............................................21
Figure 7 RS232Relay Schematic (Version E PCB).............................................22

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RS232Relay User Guide Version 3.02 Page 4 of 23
2. Introduction
Thank you for your purchase of the RS232Relay. The following instructions will
assist you in configuring and operating the product.
RS232Relay provides an easy-to-use interconnection between your Personal
Computer (PC) and switched devices. The relays used on RS232Relay can be
connected to almost any load to perform “real-world” functions.
RS232Relay has the following features:
•4 dry contact relay outputs, each with a Form C contact, that is, a normally
open and a normally closed contact, each capable of handling 100 Volts
DC at up to 1.25 Amperes, or 120 Volts AC at 0.5 Amperes.
•Capable of Momentary, Pulsed or steady-state operation of the relays
oMomentary operation is useable from 1 second to 99 minutes
•On-board LED’s to show the state of the relays.
•Interfaces directly to your PC via a spare RS232 serial port, or via any
RS232 to USB converter
•Power input of 12 Volts AC or DC at 350 mA. Optionally, power can be
provided from a 5V USB power converter connected to J7 on the front
panel.

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RS232Relay User Guide Version 3.02 Page 5 of 23
3. Installation
To complete this project, you will need to connect a 12 to 16 Volt (AC or DC)
transformer to connector J1 (see Figure 2 for the location of J1). The transformer
needs to supply at least 350mA. The polarity of the connection to J1 is not
important. J1 may be a 3 terminal connector and if so, the middle terminal is not
used. For Version D and later PCB’s, power may optionally be provided through
the USB connector J7 located on the front panel. Do not power up at this time.
Connect a standard serial cable (straight-through) between J2 and your PC.
Review Table 1 for which pins are used. Note: the USB connector J7 on
Version D and later PCB’s is provided for optional powering ONLY.
Figure 2 Location of Connectors (Version C PCB)

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RS232Relay User Guide Version 3.02 Page 6 of 23
Figure 3 Version D PCB
Table 1 RS232 Cable Connections
Pin Number
Pin Name
Definition
1
Not used
2
TXD
Data from RS232Relay to your PC
3
RXD
Data from your PC to RS232Relay
4
Not used
5
GND
Ground
6
Not used
7
Not used
8
Not used
9
Not used

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RS232Relay User Guide Version 3.02 Page 7 of 23
IMPORTANT:
Due to a Version C PCB error, the labels for J3, 4, 5 and 6 are incorrect. NO and
Care swapped on the PCB labels. Figure 3 shows how they should be
connected (J6 shown, but applies to all relay terminals). The NC contact is
correct on all connectors. This does NOT apply to Version D or later PCB’s
and the sequence of the relay connections are as shown on the PCB.
Figure 4 Corrected Relay Contacts (Version C PCB ONLY)

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RS232Relay User Guide Version 3.02 Page 8 of 23
4. Configuring RS232Relay
Using Hyperterm, or any other terminal emulation program, configure the
connected serial port to 9600 BPS, No parity, 8 bits, 1 start bit and NO hardware
handshaking. Ensure that the port chosen matches the connected serial port.
Now, apply power to RS232Relay. The default start-up sequence will look like
this:
RS232Relay v3.02 2022-01-17
www.MidonDesign.com
www.n0dim.com
Serial # 2632C0000001436ECB2D
Debug = Off
Momentary Relay Action = Off
Relay Powerup Restore = Off
Relay #01= Off
Relay #02= Off
Relay #03= Off
Relay #04= Off
Clones: None Set
The following commands will establish the parameters you need to control your
relays.
4.1. MOM
Use the MOM command to determine if you want your relays to turn off a pre-
determined amount of time after turning on. The RLT command sets that time
interval, which can be anywhere from 1 second to 99 minutes. Setting MOM on
will enable the timer functionality.
Note that if the Momentary function is enabled, you will not be able to process
any further commands to any of the relays until after the first command has gone
through the time period established by the RLT command. If you need to
activate another relay in this period, use the RTC command to clear the timer
and then proceed as normal.
4.2. RLT
Set the time delay with the Relay Timer command. Input any number from 0 to
99. The time delay is measured in seconds (if TYP=S) or minutes (if TYP=M).
RLT is not a valid command if MOM is set to off.

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RS232Relay User Guide Version 3.02 Page 9 of 23
Using a time of 0 will cause a near-instantaneous relay off whenever you turn a
relay on.
4.3. TYP
Use the TYP command to determine the type of time interval desired by the RLT
command. The options are S for Seconds and M for Minutes.
TYP is not a valid command if MOM is set to off.
4.4. SPR
Relay232 retains memory through a power failure, so if you want the relay states
to revert to what they were prior to a power failure, enable this capability with the
Set Power Restore On command (SPR on). This setting is defaulted to off.
4.5. CLO
The CLOne command provided for those cases when you may need more than a
SPDT (Single Pole Single Throw) contact closure for an external device. Cloning
a relay makes two relays operate exactly as if they were one unit and thus gives
you DPDT (Double Pole Double Throw) capabilities.
For example, if you want to use Relays 1 and 4 as a DPDT relay, use the
command:
CLO1=4
Anytime you then set or clear relay 1, relay 4 will also set or clear. The same is
true in reverse; operating Relay 4 will also operate Relay 1.
Cloning is only functional for 2 relays at a time. If you attempt to clone 3 or 4
relays together, only the first 2 will activate together.
RS232Relay ships with clones disabled. If you want to clear any clones you
have set, reset them all with the following command:
CLO0

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RS232Relay User Guide Version 3.02 Page 10 of 23
4.6. DEB
Midon Design strives to ensure the highest quality of our software and hardware.
However, there are times when problems do occur. The DEBug command is
used to enable diagnostics so that Midon Design can trouble-shoot any problems
you may encounter. Normally the debug function is off, but if you have problems,
set debug on and send us any outputs from RS232Relay. This will speed up
assisting you. DEB parameters are On or Off.