Memory lost in SLC500, can't communicate

[JesperMP]

The 1784-PCMC4 cable for PCMK-DH485 has an RJ45 port in the DH485-end, and looks like this:
http://www.***********.com/prodimg/RA-1784-PCM4-B-UPP.jpg
DO NOT PLUG IT INTO THE RJ45 PORT ON THE L551 CPU !

In order to connect from the PC to the L551 CPU by means of the PCMK & PCMC4, there must be a 1747-AIC in between, and a 1747-C11 cable from the AIC to the CH0 port on the L551. Like in this post:
http://www.plctalk.net/qanda/showpost.php?p=207859&postcount=7
(edit: Thinking again, I think it is wrong. You can go from an AIC to an L531, but not to a L551).

All this assumes the CH0 port is setup for DH485 which is not unlikely. I aggree with OkiePC that you should post the program.

If the CPU has completely lost the program, you should try to connect to it via plain serial DF1.
That requires a null-modem cable from a serial port on the PC to the CH0 port on the L551.
In RSLinx setup a "RS-232 serial DF1" device. Set "device" to "SLC-CH0/Micro/Panelview" and hit the "Auto-configure" button. If it connects and the detected baudrate is 1200, then it is almost certain that the program has been lost.

 

[sthompson]

Forget your PCMK and DH+, it isn't going to do you any good with this Processor, and you will most likely end up damaging something. Don't plug it into your SLC5/05 anymore!

As others have suggested, your best bet is a Serial Connection over DF1.

Questions:

Does your Laptop or PC you are using have a real Hardware Serial Port?

Do you have a Null Modem (Crossover) Serial Cable?

Are you familiar with the difference between a Straight Through and Null Modem Cable?

Stu....

 

[TConnolly]

Forget your PCMK and DH+, it isn't going to do you any good with this Processor, and you will most likely end up damaging something. Don't plug it into your SLC5/05 anymore!

Chances are very good something has already been damaged. Never Never Never connect DH-485 and Ethernet. Never!

cpstone, at this point you should try and establish communications using the RS-232 DB-9 connector and the serial DF1 driver. After you have confirmed that the PLC is OK, then check or set the IP address for the ehternet port while you are still connected to the serial port. Then try connecting via ethernet - but not with the PCMK card. Uplug the PCMK and put it a box and put the box on a high shelf somewhere. Then use the ethernet port on your laptop a cross-over cable, and with your laptop IP address set to a compatable address see if you can go online. Don't be surprised if it fails - you may have permanently damaged the ethernet port. If you haven't then you are a very lucky person and should take a trip to Vegas this weekend.

 

[cpstone]

hi,

i got it to work, the program was configured to use DH485 connection through channel (0) so I used the 1784-B PCMK cable to go from the computer to the back of the panelview 550. I was then able to configure the driver and connect to the PLC.

Thanks

 

[cpstone]

the RS232 DF1 wouldn't connect because channel 0 had already be configured for DH485 previously.