Control Logix Communication


Thread Starter

Justin Lund

I have a Controllogix processor running with a DH485 Panelview. This is plugged into the RS232 port on front of the processor. I need to get on line with the processor whilst the Panelview is still plugged in for commissioning and trial running. After commissioning, a modem needs to be installed for off site modifications. I understand a 1761-NET AIC could be used but the Bradley site is not much use.

Any help would be appreciated.

James Ingraham

I'm going to dodge your question slightly and tell you how I would accomplish this. Rather than programming through the serial port, add a 1756-ENBT card to to the ControlLogix and program over Ethernet. This doesn't solve the problem of a modem, but you could leave the PLC hooked up to the network at all times, then provide a PC with a modem and PC Anywhere (or Carbon Copy or Tridia VNC or whatever). This also takes care of some latency issues with modems talking directly to the PLC.

I know this doesn't really answer your question, but it does provide an alternative that works.

-James Ingraham
Sage Automation, Inc.
You obviously did not download the user manual from ABs’ web site. Just a note, one of the most user friendly and resourceful web sites around for product information and support.

The DH485 network cannot be connected directly to modem connections. You will have to involve the use of a DF1 to DH485 converter such as the 1747-KE or 1770-KF3.

I recommend using Ethernet (1756-ENBT module) to go online while commissioning the system. This approach is much simpler and will cost less than trying to build a DH485 network. (Time and material) >

I would then purchase an AB 9300-RADKIT (one of the new AB modem kits, works out of the box, no configuration needed, all cables included), and an AB 1761-NET-ENI (DF1 to Ethernet/IP)(Configuration required for I/P address, ect.). Connect the modem to the NET-ENI, the NET-ENI to the ENBT w/cat. 5-crossover cable.