unable to connect to SLC5/05 via DF1 port

[gromit 4]

Using a null modem cable, I am unable to connect to SLC5/05 PLC via the DF1 port.

I can connect via Ethernet, but not the 9-pin DF1 port on the front of the processor.

After a few attempts(many), I noticed that CH0 was set up as DH485, so I changed it to DF1 Full Duplex thinking that would do the trick, but it did not work.

Please advise.

Thanks.

Edited 2 May 2016 by gromit

[kaiser_will 65]

First, are you using a PC with a hard serial port or a USB to serial adapter?  RSLinx is very finnicky with USB to serial adapters.

Do you have any other services running that want to control the serial port?  RSLinx is very finnicky about having full control of the serial port.

Have you verified the DF1 and serial port settings on both ends?

Are you choosing the Auto Connect feature in RSLinx?  This does not work for all CPU models.  Though I believe should work for the SLC 5/05 model.

[gromit 4]

kaiser,

I tried two different usb to serial adapters, which usually work.

I am able to connect with one PLC, but am not able to connect with the referenced PLC using the null modem cable.

Usually, all I have to do is select Auto-Configure from "Configure Drivers" in RSLinx, and it reports back "Auto Configuration Successful".

This works with one SLC5/05, but not the one mentioned.

Thanks.

[Mickey 71]

If the port on your SLC is configured for DH485 and you do not have a real serial port on your PC ,then you are going to have to use a USB to DH485 converter .The 1747-UIC will do the trick.

Is anything connected to the serial port? If not then change it to DF1 protocol while connected to the Ethernet port.

[gromit 4]

Thanks Mickey. . . I thought I made it clear that I changed it to DF1 Full Duplex in my initial inquiry, but when I went back to read it I realized that I only mentioned Full Duplex while accidentally omitting DF1...so I updated the original post.

Anyway, the point is that I did attempt to change ch0 from DH485 to DF1, but still could not get the "Configure Drivers" in RSLinx to "Automatically Configure" the port, hence, I've been unable to communicate to the PLC via the DF1 port on the referenced SLC5/05 PLC, but was able to on a different SLC5/05 PLC.

Any other ideas???

Edited 2 May 2016 by gromit

[Mickey 71]

Double check the SLC's port settings and set up RSLinx to match manually. Not all USB to serial adapters work with autoconfigure or at best it's iffy.

[gromit 4]

thanks Mickey. . . I will try it directly.

[kaiser_will 65]

Gromit...the USB to serial adapters you noted, you have used these with Rockwell PLCs before?

I have had tons of grief with USB to serial connection of A-B PLCs.  Even with the same model of adapter.  I had to resort to uninstalling the drivers and reinstalling every time I connected again...until I got an old laptop with a hard serial port.

By any chance you can get your hands on an old laptop with a hard serial port?  Even if you just install RSLinx to verify connectivity.  Let Linx on the old PC auto-configure, make note of the settings, then manually set them on your development PC.

[gromit 4]

Yes, I used both ISB to serial adapters with Rockwell PLCs.

I do not have an old laptop with a hard serial port, but may have a docking station for my laptop, which I am running RSLogix500 on VMware player.

[gromit 4]

Wow. . . Mickey, I tried your suggestion to set the port settings manually and was then able to initiate the Auto Configuration successfully.

Basically, everything matched except the error checking was manually changed from BCC to CRC, and then it worked. . . now I am online via DF1 serial port rather than the Ethernet port.

The Ch 0settings are as follows::: Driver=DF1 Full Duplex//Baud=19200//Parity=NONE//StopBits=1//Source ID=0//Control Line= No Handshaking//Error Detection=CRC//Embedded Responses = Enabled//ACK Timeout (x20ms)=50//NAK Retries=3//ENQ Retries=3.

I can now get online with the SLC5/05 PLC using the Prolific USB to Serial adapter and the FTDI USB to Serial adapter loaded on my Windows7 VM.

Thanks for the help.

Edited 2 May 2016 by gromit

[Mickey 71]

You're  welcome

[kaiser_will 65]

For me, I grab a screenshot of the successful Linx settings and save that document.  And talk to IT about staking claim on an old laptop with a hard serial port, or use your docking station.  Linx, USB-to-Serial adapters and VMWare have consumed so many troubleshooting hours over the years.

[gromit 4]

kaiser, you are so right, between the USB-to-Serial adapter and VMWare drive, it is very temperamental, and you never know if it is going to work from one time to the next.

Thanks for your and everyone's help.