Allen Bradley PLC-5/40E and Flex I/O

[fredm54]

I have a PLC-5/40e that's connected to 10 remote DCM cards, each on a SLC-500 using Channel 1B in Remote Scanner mode. They are all configured as Full Racks and is functioning 100%

I have a 1794-ASB (Series C) Flex I/O Remote Adapter and a 1794-IB16 input module from some other equipment.

Anyway, I was trying to see if I can add this to the same channel (1B) using a different rack number but I cannot get it to work.

I even tried a spare PLC-5/40e on a workbench with only the Flex module on channel 1B and still cannot get it to work.

The lights on the Flex module light up when power is applied and then they all go out which I think indicates a communication problem.

Any ideas?

thanks!

 

[nightline]

Have you tried to powerup de PLC while pressing the reset button on de ASB ?

 

[Mickey]

Can you post the PLC5's program, its .RSP file ( zip it first)?

Can you post the dip switch settings for your 1794-ASB adapter?

Did you add the new adapter to the end of the daisy chain RIO network and install the termination resistor at the end of the network?

 

[fredm54]

Right now I'm using a spare PLC5/40E without a program. I do have an IO Status file and a Diagnostic file but no ladder rungs. The 1794-ASB is the only device on Channel 1B and I have a 150 ohm terminator resistor installed. I've tried the Comm Reset button but nothing changes.

I've tried all sorts of dip switch settings, ie: different rack numbers, last chassis, baud rates, group numbers. I've even tried a terminator on one and both ends (the cable is only 24") It's possible I just have a bad Flex module. I'll try again next week and maybe then I'll order a couple more and try them. Eventually, I'll need 3 of these Flex modules for this project. I'll upload the program file next week if I'm still having trouble.

thanks!

 

[Bit_Bucket_07]

I'm not saying that this is your problem, but a very short cable can be troublesome. You'd be better off with at least 10 or 15 feet of cable.

 

[OkiePC]

Be very particular about how you set up the 1794-ASB series C dip switches. Right around C or D, some of them changed, so you can't just copy the settings from a failed unit in all cases. Be sure to read the fine print and ensure the settings you choose apply to a Series C.