Omron CJ1 <-> Telemecanique Magelis XBTGT Panel (RS-422/485)

[EirikV 1]

Hi, I am having a bit of a headache over this, been fighting with it for a couple of days, maybe some of you guys can help me out. I have (several, but just one for now) a Telemecanique Magelis XBTGT1335 HMI Panel that is supposed to communicate with an Omron CJ1 PLC over RS-485. I was in contact with Schneider Electric and they told me to connect the +TxD and +RxD pins together and the -TxD and -RxD pins together on the Omron PLC (I'm using a SCU31-V1 comms card, by the way with terminating resistance ON and 4-wire) to form a plus and minus line (RS-485). These then go into the HMI panel on a RJ-45 connector connecting to pins D1 and D0, which in the manual is described as "Transfer Data (RS-485)". The HMI panel calls the driver "Sysmac Link (SIO)", there are two types of equipment available for this "C Link" and "CV Link" I've chosen the C Link one. Maybe I chould choose CV Link? Now, in the PLC there is no such thing as C Link. I figured my best bet was the Host Link protocol, since - correct me if I'm wrong - that one is open as opposed to the NT Link (1:N) one, that is closed. I've tried with several different baud rates, I've also tried both Host Link and NT Link (1:N), I've tried different modes of the Host Link protocol (Mode A, B, C and D, whatever they mean), I've tried with send delay (10ms) I've tried without send delay, I can't for the life of me get this to work. On the comms card (SCU31) I observe that the RD diode is flashing with intervals of approx. 15 seconds but there is no activity on the SD diode. The HMI panel says the PLC didn't reply within the timeout period (10 seconds). Before the weekend I managed to get some other messages from the driver saying ”PLC returned error code. ( DM) (CLink)” - where DM would be the memory area I was trying to read from - and ”PLC packet validation failed. Invalid checksum. (CLInk)". I was however not able to reproduce these today with the same settings I used then. My current settings are Magelis XBTGT Driver Name: Sysmac Link (SIO) Serial interface: RS-422 4-wire (yes, Schnider Electric told me this was the same as RS-485 on these) Transmission speed: 9600 Retry Count: 2 Parity bit: Even Stop Bit: 2 Data Length: 7 Rcv. Time Out 10 Sec TX Wait Time: 10 mSec Equipment Name: C Link Station No: 1 Write Commands: Force monitor mode (checkbox, checked) Omron CJ1 SCU31 Port 1: Terminating resistance: On Port 1: Wire: 4 Port 1: Serial communications mode: Host Link Port 1: Data Length: 7 bits Port 1: Stop bits: 2 bits Port 1: Parity: Even Port 1: Baud rate: 9600bps Port 1: Send delay (user specified): 10 ms Port 1: CTS control: No Port 1: Host Link compatible device mode: Default(Mode A) Port 1: Host Link unit number: 0 Anyone? Thanks, Eirik

[MPM 1]

have you looped 4 and 5 in scu connector. have you selected plc as unit number 1. termination in scu is 220 ohm, make sure if you use this the termination in magellis is also 220 ohm. regards

[EirikV 1]

In the manual it says that 4 and 5 is not connected on the RS-485/422 ports. I have however as you suggested looped the pins, to no avail unfortunately. I tried setting the Host Link station number on the PLC to 1, no luck there either. Is 1 the default station number for the bus controller? I thought 0 made more sense. I tried soldering a termination resistance to the Magelis end of the (short) cable, that did not do the trick either. Aren't those kind of things a bit more forgiving og such short cable lengths as I am operating with now? Approximately 50 cm. Eirik Edited 20 Apr 2010 by EirikV

[MPM 1]

Hi Eirik, please ignore the loop from 4 to 5 , my mistake. The cable is correctly created as 4 wire. scu magelis R+ ---- S+ R- ---- S-- S+ ---- R+ S- ---- R- no termination indeed for the short cable. C mode usually is referred to as hostlink. The PLC has nodenumber 0 I can see. If the magelis is correctly implemented the hostlink protocol then there should be no issue. If you can not get it to work you can always use the OMRON NQ5 which is a comparable HMI. regards,

[EirikV 1]

Hi, I got it working instantly with RS-232C, so I guess that means the Host Link protocol is correctly implemented. I have now resorted to a EX9520 RS-232 to RS-485 converter connecting the panel(s) to the RS-485 end and the PLC to the RS-232 end. Still, I have problems. I can see on the diodes on the SCU that the panel is transmitting and the PLC is answering. On the Magelis panel though I can see in the event log that the driver reports ”PLC packet validation failed. Invalid checksum." and then "No reply from PLC within Timeout period." repeating itself down the log. I have tried with baud rates 19200, 9600, 4800 and 2400. No luck. My wiring looks like this: PLC.........Converter.........Panel 2-------------3 +D-------------D+ 3-------------2 -D-------------D- 9-------------5 4-+ 5-+ 7-+ 8-+ Eirik

[MPM 1]

I do not understand this. the SCU31 as you described has no RS232. how can you run it then? regards,

[EirikV 1]

Sorry, I used the on-board RS-232 port on the PLC for that. Anyway, I have moved over to Modbus comms for this application, and it works quite good Thank you anyway for your time Eirik