agent008

A pair of C200H(CPU03)'s wired via RS422 (LK202) and CX-Programmer...

18 posts in this topic

Dear all, I'm new here and just registered because have been banging my head for weeks now without a solution. I have also posted the same question in another forum so maybe anyone who's in both forums please don't hate me :-2

Before I start let me state I searched this forum for anything similar to my doubt, but the topic that could possibly answer my question is 7 years old (http://forums.mrplc.com/index.php?/topic/17957-omron-lk202-host-link/&do=findComment&comment=85783) and the manuals linked there have old links which don't work anymore, so I thought it would be wiser to not reopen it... and just ask in a new topic?

So, to the actual facts & question....

We are based in Brazil and have some old (1993) French machinery run by 2 Omron C200h-CPU03 PLC's with attached "Host Link" LK-202 (RS422) cards. These are wired network-style and then connected to a ADAM 4570 serial/ethernet server. Since 2007 CX-Programmer has been used to connect to the CLP's and enter MONITOR mode. However since the machines came to my responsibility we have been unable to connect CX-Programmer and the PLC's in order to check the program and/or error messages! Have recently bought an Omron K3Sc-10 USB-RS422 converter (thinking the Adam 4570 could be at fault) but no luck. I try to connect but get no response. The Transmit/Receive LED's on the K3SC-10 and the LK202 do blink a few times before CX-P gives me the error. What am I missing? Anyone have a clue, maybe it's the wiring? Thank you.

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What are the rotary dials on the front of the LK202s set for?

Here is the manual:

C200H-LK202-202 manual

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Hey, thanks for the quick Answer! 

One PLC has the LK202 dialed to 0-0-5-2. (Unit 00, 9600BPS-7 data bits-Even Parity-2 Stop Bits, Ladder Software). The other C200H is dialed to 0-1-5-2(so, Unit# 01, other params the same as Unit#00). Both LK202 units have the back switches set as Terminator resistance ON and network type 1:N.

The K3SC-10 is set to 9600BPS-7 data bits-2 stop bits, and Pin 9 of the DIPswitch is on to indicate RS232C to RS422 conversion!

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Are you using USB or serial to connect to the computer?

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Tried both:

1-Serial:

computer (2007 HP PC with XP)>Adam 4570 (RS232C)>Omron K3SC>RS422 Link Adapter>CLP's (Link Unit 00 and 01).

2-USB:

laptop(2004 HP Laptop with XP)>Omron K3SC (via USB)>CLP's (Link Unit 00/01)

Thanks in advance

Edited by agent008
typos

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How is the com port wired between 2007 HP PC and Omron K3SC com port?  (Pin to Pin)

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I'll check it tomorrow and let you know. Thanks so far!

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Here is how the HP Desktop is connected to the K3SC:

Computer ====ethernet connection====>Adam 4570 Serial Port 1====Shielded Cable====>K3SC====Shielded Cable====>LK202

I can verify that communications between the HP desktop and the Adam 4570 Serial server work perfectly (have connected another computer to the Adam and tested via Hyperterminal/Putty).

Wiring between the ADAM 4570 RS232 and the K3SC RS232:
Adam                                                        K3SC             
Pin 1 not connected
Pin 2 (RX)--------------------------------------Terminal 5 (SD)
Pin 3 (TX)--------------------------------------Terminal 6 (RD)
Pin 5 (GND)-----------------------------------Terminal  3 (SG)
Pin 4 (DTR)---| (jumped to pin 6)
Pin 6 (DSR)---| (jumped to pin 4)
Pin 7 (RTS)------| (jumped to pin 8)
Pin 8 (CTS)------| (jumped to pin 7)
Pin 9 not connected

(Although you didn't ask, better err in excess than lack of information...) Here's the wiring between K3SC RS422 and LK202:

K3SC                                                        LK202         
Terminal 7 (SG)-------------------------------Pin 3 (SG)
Terminal 8 (RDA [-])-------------------------Pin 9 (SDA)
Terminal 9 (SDA [-])-------------------------Pin 6 (RDA)
Terminal 10 (NC) not connected
Terminal 11 (RDB [+])----------------------Pin 5 (SDB)
Terminal 12 (SDB [+])----------------------Pin 1 (RDB)

Thanks

Edited by agent008

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(posted this on the other forum and think could be of help to understand the problem here too...)

Before I got a hold of the K3SC converter, the setup was connected to the Adam 4570 (set up as RS232) by means of a Dataforth LDM35 (kind of a RS232C range extender with RS422 to RS232 conversion capability by just addin a zenerg diode between 2 of its pins). The LDM35 went bust and since I couldn't find one easily, I got the K3SC. Could it be that the LDM35 was not only converting the signal but actually also amplifying it? Thanks

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If it is a range extender I would imagine it would be amplifying the signal. That is what they do.

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Right. Will try to find something similar. The wiring looks ok?

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Your Adam 4570 supports RS422 directly.  Why do you need another convertor(K3SC)?  Also RS422 standard supports up to 500 meters.  Is your distance longer than this?

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Quote

Pin 2 (RX)--------------------------------------Terminal 5 (SD)
Pin 3 (TX)--------------------------------------Terminal 6 (RD)

Try flipping Terminal 5 and Terminal 6.

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Hi.

9 hours ago, Jay Anthony said:

Try flipping Terminal 5 and Terminal 6.

Thanks! Will try that tomorrow.

 

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9 hours ago, Jay Anthony said:

Your Adam 4570 supports RS422 directly.  Why do you need another convertor(K3SC)?  Also RS422 standard supports up to 500 meters.  Is your distance longer than this?

It was one of the first questions I had myself, but the machine was already set up that way (using the LDM35 configured as a converter). Since I snagged the K3SC practically for free it was worth a shot. About the distance, it is very short! Adding up all RS422 cable length wouldn't even pass the 10 metre mark...

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On 08/08/2016 at 6:53 PM, BobB said:

If it is a range extender I would imagine it would be amplifying the signal. That is what they do.

Found an Adam 4510 RS422 range extender/amplifier. A couple days it'll be here and I can test with it...

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18 hours ago, agent008 said:
On 09/08/2016 at 10:26 AM, Jay Anthony said:

Try flipping Terminal 5 and Terminal 6.

Thanks! Will try that tomorrow.

 

Good Morning all

So, tried swapping 5 and 6 ans suggested and it is a no go -- at least before the XMT/RCV LED's would blink on the LK202's when trying to connect, after flipping the wires nothing happened. Since the K3SC can be set up (via DIP switches) to act as a USB-RS232 converter too, I disconnected the RS422 network from it and connected a laptop to the K3SC's USB connection. So that both the desktop and the laptop would be connected to each other as a kinf od null modem. Opened Hyperterminal on the PC and on the laptop. Without flipping 5&6 I could send characters from one computer to the other. After flipping nothing would be sent, so I'm assuming 5&6 are connected the right way...

So, with 5&6 back in place I opened CX-Programmer on the desktop and left Hyperterminal connected on the laptop.

Every time I tried to connect on CX-Programmer to Unit 00, the laptop would receive "@00MB1A03003C*" and a carriage return. For Unit 01 it would get "@01MB1A03003D*" and a CR.

Last of all I reconfigured the K3SC for RS232 to RS422 and put back in place the cable from the K3SC to the 422 network, went to the desktop, opened a terminal session and typed the codes above myself. With each keystroke the RCV LED on both LK202's would faintly blink for a split second. When I hit enter (carriage return), the XMT LED on only one Unit (depending on the sequence I typed) would blink once and my terminal would show "s&bbQbb" and a carriage return...

So it seems the connections are OK, I will now research what the response "s&bbQbb" means. 

Thanks

 

UPDATE: from W182 (SYSMAC Host Link Units System Manual) I can see that the response I'm getting is wrong i.e. not on the correct format. I am now scratching my head thinking I might have a "send data" (SDA with SDB) pin inversion on the cable which goes from the LK202 to the K3SC.

Is it possible that inverted Send Data A / Send Data B  wires would cause garble text to come out? Or the expected outcome would be no output at all?

Also I noticed that while the XMT led from the LK202's does blink, the RD led on the K3SC doesn't. Which also tempts me to inver the SDA/SDB wires...

Edited by agent008
Update information

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Update:  there was some kind of transient current coming through the 422 wires which we traced to the 24V power supply. After I plugged in the Adam 4510 range extender, the transient was amplified and was enough to burn the K3SC's USB connection (ie. stopped being recognized by the laptop)! I suspect this was the cause of the garbled responses from the LK401's.

We have rewired the PLC's into a new PSU, the transient is gone. Will now try to connect the LK401's directly to the Adam-4570 as suggested before.

 

Thanks

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