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Unresponsive serial port of Omni LT controller

How do I reset Omni LT controller board which is not responding to serial port/PC Access? Is there a way to do it without disconnecting the battery?
I access the serial port of our old Omni LT controller via an external serial-to-ethernet board (so that I can access it from anywhere).  The serial-to-ethernet board seems to be working fine.
The error messages I see on PC Access are "Comm Status: Unexpected Error (53) followed by "Comm status: No reply (1)".  I did not change any of the communication setting such as baud rate, etc.
BTW, is there a way to fix this serial port issue without resetting the LT panel?


Has it worked in the past?
Are you seeing communications issues with your serial consoles keypads or serial thermostat or serial omnitouch screens?
Ideally for just a few minutes you should power down the panel and disconnect the battery then restart everything.
The board design is based on the boards serial bus.  The board design evolved to using Ethernet talking to the serial bus.

Here continue to access one port on the OmniPro 2 panel for an old automation program. I have used that port to connect to PCA serially.
Thanks for the response.
Yes, it always worked since I set it up 2-3 years ago except once the 5V power supply to serial-to-ethernet failed.
BTW, I could resolve the mystery today.  I could finally fish out a serial to USB cable from my junk collection and connect a laptop directly to the LT panel to find that everything works fine.  So, now I have to get a replacement for the bad serial-to-ethernet thingy.


Good news. 
Must have been the bad 5V power supply to the serial to ethernet board.
I used to see these up on Ebay used.
LQtechvn said:
what protocol you choose?
That's a good question.
I choose the baud rate as specified in PC Access: 9600, which apparently is the only serial communication parameter one can select in PC Access other than "Omni-Link" (under "Function" in Setup|Expansion|Serial in PC Access).  
Maybe "Omni-Link" spec defines the other RS-232 specs, which I have no clue.  Anyone knows the specs of Omni-Link?
In any case, it used to work with: RS232, parity: none, char: 8, stop bits: 1, flow control: none.  I didn't change any of those.


I have a serial port to PC connection on the OmniPro 2 panel (all of the serial ports are being utilized today).  (UPB, Zigbee, ZWave, X10, Russound....) 
Its been connected now for almost 20 years of use.   

OmniPro application is running on a Windows server box standard com 5 connection at 9600 baud 8N1.  
The OP2 serial protocol document serial communications is documented here:  
Omni-Link Serial Protocol Description (2003)


now I have to get a replacement for the bad serial-to-ethernet thingy.
What is the serial to Ethernet board MFG / Model number?
pete_c said:
now I have to get a replacement for the bad serial-to-ethernet thingy.
What is the serial to Ethernet board MFG / Model number?
The old one was:
Serial Ethernet Converter (RS232, RS485) - PRO
I don't recommend it as it often hangs and I had to power-cycle it every week or so.
The new one is:
StarTech NETRS2321P
which is working fine so far even though it was a pain to change its default setting from static IP to DHCP.


Active Member
Omni controller should no-reply wrong message. using ProLink for simple integrate or need to make app follow OmniLink serial protocol


Get one of these from Amazon:

PUSR USR-TCP232-302 Serial RS232 to Ethernet TCP IP Server Module Ethernet Converter Support DHCP/DNS
pete_c said:
Get one of these from Amazon:
PUSR USR-TCP232-302 Serial RS232 to Ethernet TCP IP Server Module Ethernet Converter Support DHCP/DNS
I saw it on Amazon, but there were no user reviews for it 2 years ago and even now.


I see bad reviews on it.  Automation peer purchased it last week and could not get it to work with Linux...IE: just Windows...
Here use Ebytes LoRa transceivers and they work well except that they are 1 Watt and go a mile and are not FCC approved.  Thinking they sell 100 Mw transievers.
These are cheap on Ebay.
I am using one for RFID and it works from the garage to the basement server room.
Found an "el cheapo" one for around $7 USD on Ebay.  Serial server.
CH9121 Serial Port to Ethernet Network Module Serial Server STM32 Networking New


Its on Amazon for $11 or so...

Taidacent CH9121 Ethernet Serial Port Server Serial Port to Ethernet Adapter Single Chip Microcomputer Networking Module Supports TCP CL .IENT, TCP Server and UDP CL IENT, UDP Server Modes
Not sure but you may need a TTL-RS-232 converter for it.  Cheap though as I am using one for a test GPS/PPS NTP server...
Here are 6 for $7 on Amazon.

HiLetgo 5pcs RS232 to TTL Converter Module COM Serial Port Board MAX3232 MAX232CSE


Specs require TTL to RS-232...
Product parameter:
1. Built-in Ethernet media transport layer (MAC) and physical layer (PHY)
2. Realize two-way transparent transmission of serial data and network data
3. Support 10/10OM, full duplex/half duplex adaptive Ethernet interface, compatible with 802.3 protocol
Support MDI/MDIX line automatic conversion
5. Support DHCP to automatically obtain IP address, support DNS domain name access
6. Set the chip working mode, port, IP and other network parameters through the host computer software/serial AT command
7. Working mode supports TCP CLIENT, TCP SERVER and UDP
8. The serial port baud rate supports 30Obps~92160Obps
9. String D TTL level, compatible with 3.3V and 5V
10. Serial support full-duplex and half-duplex serial communication, support RS485 transceiver automatic switching
11. Support DHCP to automatically obtain IP address function
12. Support 0~2000ms serial timeout time setting
13. Support DNS domain name system
14. Support KEEPALIVE mechanism
15.Supply voltage: 3.3V/5V

If you puchase all of this stuff on Ebay you can DIY it for $10.
1 - CH9121 serial to Ethernet server
2 - TTL to RS-232 device.