AB ControlLogix 1756 comm.

Folks,
I am new to AB, we are using a 1756 L1M1 rack. My first trouble is the cost of communication to the system. The 1784-PCMK pcmcia card for laptop is over $1000, the cable 1784-PCM6 is around $200. Just wonder if any way to use a RS232 cable to cummunicate to the 1756 CPU system.
Thanks

you can use convertor cable (USB to RS232
regards

The 1784-PCMK is an unusual way to communicate with ControlLogix, as it is a Data Highway Plus (DH+) network card and your ControlLogix system would also require a 1756-DHRIO module.

The serial port on the 1756-L1 controller itself is an ordinary DTE-type RS232 port. Use a null-modem serial cable (like the A-B 1747-CP3 or 1756-CP3) to connect the controller to your PC. You can upload, download, monitor, and bridge through to other networks via this local RS-232 serial connection.

the natural way to connect is to use the rs232 cable .
the 1784-PCMK pcmcia card only purpose to connect the cpu from a distant location via the dh+ network .

You can use the serial port on the CLX processor as stated above but this will be horribly slow if you need to work on this system regularly. If you expect to be working with Control Logix on a regular basis and your system(s) have spare slots in the rack(s) my advice would be to keep a spare Ethernet card and use this. The cards can be inserted and removed while the PLC is running and you have the added advantage of having a spare available should you need one in an emergency.

Andybr

I will try out the RS-232 speed. I get used to the other PLC systems and I'm ok with 56k speed. If the A-B 1747-CP3 or 1756-CP3 test out ok, you guys just save me a bundles.
Thank you guys.

HERE is another $20 or so saved

As mentioned above you can use a regular straight through serial cable with a null modem adapter. Most local electronic stores carry them cheap.