Unable to configure rs232 in rslinx

[Scrabble]

Hi i'm fairly new to plc programming. I'm having an issue connecting to a logix5555 plc with an rs232 cable. The linx and logix software has just been installed and hasn't connected to any plc using rs232 before.

When i attempt to configure the driver i get the error message "Can't find baud rate and parity"

I've tried every combination of baud rate and parity without any success. Is there some sort of driver software needed or do i need to configure it through the kepware software??? I'm at a total loss as to why i can't get it to work

 

[dmargineau]

Welcome to the Forum!
First of all, what type of cable and RSLinx driver are your trying to connect to the L55 CPU with?
Do you have an RS232 Serial Port on the machine running RSLinx or you are using a USB-to-Serial adapter?
You will need a 1756(1747)-CP3 cable and an upper tier USB-to-Serial adapter if your PC does not contain a Serial RS232 port; the Forum's choice for Allen-Bradley products is the Keyspan USA-19HS (http://www.tripplite.com/en/products/model.cfm?txtModelID=3914)
Once the above hardware configuration is implemented, you will have to configure an RSLinx DF1 type driver.
Usually the "Auto-Configure" RSLinx DF1 driver configuration utility (pointing to the proper Comm. Port #- either on-board RS232 or USB-to-Serial) is sufficient to connect to the L55 CPU's Serial Port if the default port settings have not been previously modified.
Refer to Chapter 6 of http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um001_-en-p.pdf
for CLX Controllers Serial Port communications configuration/settings.
If all the above fails, you will need to connect to the CPU via a different protocol and verify the CPU Serial Port settings; the easiest way to do it is by inserting a EtherNet/IP bridge (1756-ENBT)into a Local Chassis empty slot, patch to RSLinx running PC into the Ethernet bridge and then trying to connect to the CPU using an RSLinx EtherNet/IP driver.

 

[xC0MMAND0x]

Here's how to check the settings on your computer to make sure things match up - just as a reference in case you didn't know. This will show you what the COM port on your laptop/computer is running. If you're using a USB-Serial adapter, the same logic applies. Find the device in your Device Manager and edit the settings for to match.

Screenshot 1


Screenshot 2

 

[Scrabble]

Thnaks for the replies

I'm using a normal rs232 cable from an rs232 port on my laptop. I've check the port settings in device manager but i can't guarentee that the default port settings on the controller haven't been changed. The controller is 1756-L55.

I've tried to connect via ethernet through the ENBT module but got the error message "Comm. error 01E00204" although i didn't do this through a patch i tried to do it point to point.

 

[dmargineau]

An "ordinary" Serial RS232 cable will not do unless it is "tweaked" in order to replicate the 1756-CP3 cable pinout.
http://literature.rockwellautomation.com/idc/groups/literature/documents/in/1756-in046_-en-p.pdf
What do you mean point-to-point Ethernet connection?
Do you have a 1756 Ethernet bridge within the CLX Local Chassis?
Is your PC physically connected to the Ethernet bridge's subnet?
Does your PC NIC have a compatible IP Address to the ENBT bridge's one?
The comm.error you are experiencing is a communications timeout.

 

[Scrabble]

The rs232 cable may be the issue. I don't think it's a 1756-cp3.

Sorry by point to point i mean pc directly connected to the ethernet module.

I'm not sure what the PC NIC is

 

[Donnchadh]

Hi

Do you know the ip address of the Ethernet card. Is it scrolling across the front of the card and if it is let's say Its 192.168.2.13 then change your laptop ip to 192.168.2.33 and then in the run command Window type ping 192.168.2.13 and press enter. If it does not come back with a reply then linx can not connect then.

It you have the plc program you could post it here or the settings for the serial port can be checked within the processor properties tab


Donnchadh

 

[Scrabble]

I've sorted the rs232 problem. I wasn't using the correct cable.

I will look into the the ethernet issue

Thanks for the replies

 

[dmargineau]

The rs232 cable may be the issue. I don't think it's a 1756-cp3.

Sorry by point to point i mean pc directly connected to the ethernet module.

I'm not sure what the PC NIC is

A PC NIC (Network Interface Card) is your PC's Ethernet port access hardware.
The settings (if the user carries System Administrator credentials) could be accessed via Start/Control Panel/Network Connections (Networks and Sharing Center)/Local Area Connection/Properties/Internet Protocol TCP/IP (Internet Protocol Version 4/TCP/IPv4).
In order to successfully connect an EtherNet/IP (Ethernet) RSLinx driver to an ENBT subnet, your PC NIC will have to carry an IP Address which is compatible to the CLX Ethernet bridge's one (identical first three octets) and an identical Subnet Mask.