DH+ on SLC and CLX

Hi,

I have a CLX with 2 DH+ connection connected to it. Channel A and Channel B.

on the channel A, I only have 1 slc connected on the network. The SLc adress is 2.

On the channel B, I have a couples of SLC connected. Addresses 2-3-7-11-12-13 are used.

I'm wondering if the SLC connected on the channel A can affect the SLC connected on the channel B on the node 2.

Sometime I loose the connection with the SLc o the Channel B node 2 and I'm not able to reset the connection because I'm not able to go online with RS232 cable!?!

thanks
Martin.

I have plenty of systems with channels A and B using the same node. It has never been a problem. The more likely scenario is an improperly terminated cable. Verify resistors on both ends and the system is in daisy chain network (not star).

I've also never had the problem of not being able to get online serially. Are you using the correct baud? What are the lights on the processor doing? A little more information might help us troubleshoot it better.

Ok

I'll check for the resistor, but what is stange, is I alsways lost the connection of the PLC in the middle of the line. the DH+ led stays on and red.

For the serial connection,here is what I have. I try using
CH0 system


CH1_system


RSLINX

Do you regularly go online via the serial cable?

If so, why? If it is because you do not have a DH+ card, then you could use the ENBT in the ControlLogix (if you don't have one, you should get one), and bridge through the DH+.

As recommended before, go through the DH+ connections with a fine toothed comb. A lot of errors are caused be poor workmanship when inserting the cable ends into the terminals. Stray strands cause "ghostly" things happen to the network. In addition, make sure that the DH+ network is daisy chained.

You guys might roast me.

I had a sweet DH+ layout 4 504's and 2 computers with ktx cards and one with a pktx and never had any problems to speak of, I added a DHRIO and had many many problems.

Nodes would drop off the end, or just disapear, RsView would report time outs, and others.

I read a tech note that said use only 82 ohm resistors with the DHRIO, and my problems all but disapeared.

Strange, but it worked, I can't explain it but works much better now

Clint

I made a mistake in my first post. The CLX has a RIO/DH+ card. Ch. A is used as an RIO and CH. B is used as an DH+

I only have problems with the DH+ and always the same node failed. Node 2.

Maybe I can change the resistor for a 82 ohm.

For the network, the CLX has 2 DH+ cables going in.

Martin.

Oakley said:

Do you regularly go online via the serial cable?

If so, why? If it is because you do not have a DH+ card, then you could use the ENBT in the ControlLogix (if you don't have one, you should get one), and bridge through the DH+.

As recommended before, go through the DH+ connections with a fine toothed comb. A lot of errors are caused be poor workmanship when inserting the cable ends into the terminals. Stray strands cause "ghostly" things happen to the network. In addition, make sure that the DH+ network is daisy chained.

Click to expand...

Actually I would like to go online via the serial cable to know the reason why the DH+ led is red and fix the problem without restarting the PLC. The machine is stopped 8hrs/wk during the weekend..