Student research on DH-485 Network

Hello all. My partner Sean and I are college students working on a PLC networking project. We are new to the forums, so please pardon any simple questions or mistakes we may make.

To fulfill requirements for an R&D class, we have to network 3 AB MicroLogix 1000 PLCs across a DH-485 network using AIC+ network modules. We desperately need help, as we have hit a stopping point.

First, we wired the network using a network cable with four wires inside. The cable runs across 4 AIC+ modules, and has the 5th and 6th pin connected on either side to utilize the terminal resistor inside, as well as grounding one side via the first and second pins.

Next, we have configured a PLC to run on the DH-485 protocol using the following technique:

Project ==> Channel Config & selected the radio button for DH-485. We set the node address at 1.

Unfortunately, this is where we are stuck. When we connect as shown, we get no response from the PLC.

PC ===(9 pin serial cable)=== AIC+ ===(4 wire network cable)=== AIC+ ===(8 pin HHP Cable)=== First PLC.

Please let us know what we are doing wrong, and keep in mind that we are novices.

Thank you very much!
-Bill T.

Bill and Sean,

What driver are you using in Linx? Do you have the manual for the AIC? is it AIC-NET? What node # is your PC?

Here is the manual if you need it. It maybe easier to get one ml1000 talking at a time then add another. Each ML1000 defaults to node 1. Your pc is node 0. You have to have a driver to cummunicate with the plc. So depending on which one you have you will set it up in RSlinks. More information on your driver would help. Do you understand what a driver is? You can also do a search on dh 485 on this site. There are some good threads.

Dh-485

you will need to check that you are using the correct RSLinx driver for your AIC module. You are asking your PC to hook up directly onto the DH-485 protocol which is critical for timing. As such some PCs will have trouble, and any other software trying to use your comm port will give you trouble. Do not try and use a DF1 driver unless you have a KE module, which converts from DH-485 to DF1. note: DF1 is more friendly for your PC to use.

Instead of using network cable check the communication directly with the processor


the cable form the PC to the AIC + should be CP3 cross cable

2------ 3
3------ 2
5-------5

if everything fine PC will communicate

Thanks

Many thanks to everyone who contributed. We now have a network established!