SLC5/03 CPU/DH485 Link Coupler/ Node Help

Hi
Im after some help again.
Ive just been diagnosing a communication problem.
The system comprises Windows 98 PC running OEM Software.
Linked to an Allen Bradley RS232 to DH485 interface.
Then down to the factory floor daisy chained to 6 machines (1,2,3 ,5,6,7)(machines 4,8,9 sold).
Each machine comprises a DH-485 Link Coupler coupled to SCL/03 CPU.

This is an established installation ie has been working for years.

Fault, reported as no comms from pc to the machines.
I attend site to find no LEDS flashing on the DH485 interface next to the PC.
On disconnecting the DH-485 at the Link Coupler on all machines, then connecting just m/c 1 , we had flashing DH-485 LED and RS232 LED when requesting to connect to machine 1, consequently we established good coms on m/c1. We discovered re connecting DH-485 Link Coupler of m/c 2 or 5 stopped DH-485 LED flashing, killing the coms.

Further Investigation showed that m/c 2 coms fault was due to the coms port in the PC/OEM Software being set for com port 2, we changed this to com port 1 and m/c 2 will now communicate.

m/c 5 has a history of the SLC5/03 CPU being replaced due to another fault , the program of which we believe was held on the plug in memory module and transferred across to the new cpu, this fault was cleared and m/c 5 worked but without coms.

We suspect it was replacing the CPU that initiated the "no coms" fault.
We suspect this may be because the "Node" has not been set up in the new replacement SLC5/03 CPU.

Question: is the node number held in the memory module thus making fitting a replacement cpu straight forward. Or do we have to connect a laptop to the CPU manually set the NODE?

Hope you can help please

micgent

micgent said:

Question: is the node number held in the memory module thus making fitting a replacement cpu straight forward. Or do we have to connect a laptop to the CPU manually set the NODE?

Hope you can help please

micgent

Click to expand...

The memory module should hold everything including the node number, but your symptoms do sound like a missing or duplicate node number.

Is it possible that the CPUs were traded between machines at some point in the past?

I would recommend verifying the node numbers of all the nodes.

OkiePC said:

The memory module should hold everything including the node number, but your symptoms do sound like a missing or duplicate node number.
Is it possible that the CPUs were traded between machines at some point in the past? I would recommend verifying the node numbers of all the nodes.

Click to expand...

The "Hand of God" is possible with this customer, however in their defence the old CPU was labelled for machine 5, so I suspect they have not been swapped.

I tried to verify the nodes, but not sure how.(Im not proficient at this)
Problem is I could not get on-line directly with my Laptop, RS-Linx would not connect.

I can get online in the workshop with my test PLC SLC5/01 using RS-Linx. But could not get online when on site!

I think I need driver help for this problem.

Thank you, hope you can help further.

micgent

What is connected to the serial port of each 5/03?

You might try connecting to that port using the 1747-CP3 cable and a df1 driver in RSLinx. It is possible that the serial port on the 5/03 is being used and configured as DH485 or ASCII, and looking in a copy of the RSLogix500 program at the channel configuration should tell you.

Connected to the 9 Pin Serial of the PLC5/03 is an HMI (Not Allen Bradley).
--------------
Im using a 1747-UIC USB/DH485 interface with 1747-C13 SER B cable to connect Laptop to the RJ45 socket of the CPU.

DF1 Driver I have not tried I will visit the factory in the morning and try.

Thank you for your assistance I will let you know how I get on.

Regards

micgent

Well at last , after days of trying to dig my car out of the snow I managed to visit the customer.
Armed with a serial lead I set up DF1 driver and tried to get comms working with RSLinx.
Cable detail here
http://www.ecgf.uakron.edu/grover/web/ee491/apparatus/PCtoSLC_Cable.pdf
But it just would not work.
So I ended up using the USB(DF1) interface 1747-UIC switch set at RS232. Psu the serial lead and DF1-2 Driver. This worked.

With comms established I opened up the explorer tree, looked in the Uprocessor and noted node was set at 7, I changed it to 5, saved, cycled the power. Customer tried the coms which worked.

Okie PC

Thank you for your help, please enjoy a virtual Pint on me.