SLC 50/4 RS-232 Communications problems

Hello All,

First time poster here..

I've searched the forums with no luck on my issue.

I'm attempting to establish communications between a Uticor PMD 180 and a SLC 50/4. My first goal is going online with the PLC to determine what the settings of the other device should be.

Laptop:
windows xp service pack 3
rslinx classic pro revision 2.56.00.13 cpr 9 sr 2
rslogix 500 version 8.10.00 (cpr 9)
computer has serial port (com1)
using null modem cable

In my searches i've read that SP 3 can be problematic, not sure if that is part of the problem

PLC:
SLC 50/4
1747-L541
not sure what information is needed off the PLC

I've selected the RS-232 DF1 Devices driver and configured it for
COM1
Device: SLC-CHO/micro/panelview
baud: 19200
station number: 1
parity: none
Error check: BCC
stop bit:1
protocol: half duplex

When I clock auto configure I get the message "auto configuration successful"

The rs232 led is lit, dimly, but lit on the CPU with these settings.

I go to RSwho and the plc doesn't show.

Any ideas? My apologies if this has been asked a million times before, i'm new at this and my searches didn't provide any answers for me. Please let me know if any additional information would be helpful.

Thanks in advance,

JP

Try "Full Duplex" (default setting)

And "CRC" (default setting)

Do you have a copy of the offline program? If so post it here, we can look . Zip it first.

I just tried switching both parameters individually and together and linx failed to find baud and parity.

i'll try to get the file uploaded

johnplatt55 said:

I just tried switching both parameters individually and together and linx failed to find baud and parity.

Click to expand...

It spossible the SLC's port is not at its default settings.

Do you have a copy of the offline program? If so post it here, we can look or you can. Zip it first.

hope this works....

There are two plcs and two hmi's (pmd180) on site here. cannot go online with either plc but one hmi will communicate with either plc. the other will not work with either of them.

The port on your SLC is set for DF1 Half Duplex Slave. ( see picture for how the port is setup)

You will need to use the "DF1 Polling Master Driver in RSLinx.

Sounds good, by looking at the program do you see any parameters that would need to be changed in the df1 master setup?

my first attempt at it doesn't isn't yielding any results. I've also lost my dim led rs232 led on the cpu

Thanks so much for helping me out with this

Define polling list to add nodes you want to poll.

Double check port configuration to match the SLC and comm port your computer is using.

DF1 Half Duplex can be tricky to set up for RSLogix operations. Unless you really need it for that port, I would change it back to "normal" to simplify things for you. But first you have to "get in".

I recently had to connect to a Micrologix which required this protocol in order to communicate with a master over radios and I found a document very helpful to me:

pdf:
Publication 1761-WP003A-EN-E

EDIT: and this thread was even more valuable:
http://www.plctalk.net/qanda/showthread.php?t=6877

OkiePC said:

DF1 Half Duplex can be tricky to set up for RSLogix operations. Unless you really need it for that port, I would change it back to "normal" to simplify things for you. But first you have to "get in".

I recently had to connect to a Micrologix which required this protocol in order to communicate with a master over radios and I found a document very helpful to me:

pdf:
Publication 1761-WP003A-EN-E

Click to expand...

To make things worse I think the new device he is trying to connect is ASCII.

The OP may want to consider another method of connecting to the SLC.
1784-U2DHP ( USB to DH+ converter). OR set up the serial port to swithch modes ( user to system)

Mickey said:

Define polling list to add nodes you want to poll.

Double check port configuration to match the SLC and comm port your computer is using.

Click to expand...

unfortunately I don't know what the heck i'm doing and don't really know where to start figuring out a polling list. You were right on rechecking port configurations, had that messed up. Even with the baud rate set correctly now i'm not getting anything through to the plc.

I have a 1747-UIC converter but i'm not sure that adding in usb to 232 is going to simplify things.

Thanks for the PDF going to reread that now

don't really know where to start figuring out a polling list

Click to expand...

When you configure the driver click on "Define Pollin Lists" then add 1 to the priority stations. ( Node 1 is your SLC)

See picture

The 1747-UIC is a USB to DH485 converter it would only work if the serial port on your SLC5/04 was configured for DH485 protocol.

I was able to find the manual for the PMD180. From what little reading I did it looks like the SLC’s channel 0 port is probably setup correctly including the error checking (set at BCC). With that you do want to use a DF1 Polling Master driver in RSLinx.
http://www.uticor.net/downloads/manuals/PMD 180.pdf