CompactLogix To SLC5/03 Comms

I am a little unclear on the msg type and path to use to read information from a SLC 5/03 into a Compact Logix. I have been sucessful in configuring communications using the ethernet port on the compact logix and SLC 5/05 but this is the first time I've tried to use the serial port on the Compact Logix.

I have never done it before but....

The path for your message in the CLX should be 2,1
Where 2=out the serial port of the controller, 1=the DF1 node number of the SLC. It would be an SLC typed read or write message.

I am not sure of the cable you need for this. Maybe Null modem maybe not? I am sure someone on here will know.

RSL

Thanks for the information. I have tried 2,5 (5 is the node ID of the SLC) but no comms yet. I am curios as to why the light on CH0 of the compact logix doesn't light up when it is suppose to be attempting communications.


BTW, the path I tried was Local,2,5

Are you able to browse to it when you configure the message?

CAn you enter just 2,5?

What error is being generated in you message block?

RSL

I get an the error 'Link Address Not available'. I tried to enter just 2,5 into the path but it didn't like that. I did try and browse to the SLC but it doesn't show up in the browse window... I know the comm path is OK because RS Linx sees the SLC as a device off the Processors' DF1 port on CH0

Thanks again for the advise
Karl

How exactly are your two controllers connected together ? Depending on the model, the CompactLogix may have one or two serial ports, and the SLC-5/03 has a DH485 port and an RS232 port.

What are the protocol and port configurations of the two ports that are connected ?

You don't want the "Local" segment in the message's CIP Path string, because that sends a message to the I/O bus, like if you were sending a message out a DeviceNet scanner.

You want the first number in the Path string to be "2" for serial channel 1, and "3" for serial channel 2.

The second number of the Path is the target node number. It should be ignored if you are using DF1 Full Duplex, but has to be the node number of the SLC if you're using DH485.

The compact Logix and SLC 5/03 are joined by a null modem cable and have the same communication parameters. The Compact Logix is an L35E so I believe the serial port is Ch0. The SLC has 2 port a DH485 and a serial port. I use the Null modem between CH0 on the Compact Logix and CH0 on the SLC 5/03.

So what you are saying is for me to remove the Local at the beginning of the path and strictly use numbers ? I will try that.

Thanks
Karl

Yes, make the path "2, x", where x is the DF1 address of the SLC-5/03. I think the destination address might be ignored in Full Duplex mode, but it can't hurt to make it correct.

Another detail that might not be obvious is the default error checking mode.

SLC and MicroLogix controllers use Cyclic Redundancy Check (CRC) error checking with DF1 protocol.

ControlLogix family controllers use Block Character Check (BCC) error checking with DF1 protocol.

Both can be set to use either mode; try setting the CompactLogix to CRC.

With a path of 2,5 (5 is the destination) or 2,0 seems to be working. Thanks for the insight and all the help Ken and RSL !

Karl