T J SHARON

OMRON CJ2M-CPU13 - SCU32- Communication

22 posts in this topic

HI , 

Thanks a lot for the reply & help on previous topic.

Now i setting up a new system with 2x CJ2M CPU13  and 2x SCU32 and the connection via 1000M RS485 cable.

May i know the best communication to use for the serial communications?

 

Regards,

TJ SHARON.

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Just my two cents.

Probably your best bet would be to use CJ1W-CIF11 RS485 adapters on the cpu serial ports.

That way you could use PC Link.

gtsuport

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hi gt support, 

Thanks a lot,

That was the initial plan. But we have to use CPU serial port for HMI.

That is the reason we are planning to add SCU32.  Which Protocol would be the best to use to connect two SCU32 via 1000M

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My suggestion would be to connect the HMI to the SCU unit.

Do you already have the SCU's?

You can set the SCU for Host Link mode to talk to the HMI.

PLC Link will be the easiest way for the PLC's to communicate.

How much data are you trying to transfer?

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hi gt support, 

Thanks a lot,

Yes. I have the  SCUs. SCU32.

Ok. Do we need an adaptor for serial port to rs485 if am using the serial port in CPU?

If we go with SCU-SCU, can i use HOSTLINK?

 

 

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Adapter  CJ1W-CIF11 would be needed on the cpu serial ports.  RS232 spec is 50 feet, pretty sure it would not go 1000 meters.

You could use HOSTLINK, but you would need to format the strings.

Might be easier to use Protocol Macros.  CX-Protocol is used to create the protocols.  Another software to learn.

gtsuport

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You could also just use No Protocol mode and use the RXDU and TXDU ladder commands, easier than Protocol Macro.  

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Thanks a lot micheal,

Does"no protocol' work with 1000m cable?

Do you have any sample code or video?

 

thanks a  lot.

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No Protocol means there is no formatting to the information.

Look at the RXDU and TXDU instructions in the programming manual.  The ___U is the instruction for the SCU modules.

Check this download for information on the non module instruction  RXD-TXD quick start .

This will required logic in your program.

It should work for the 1000 meters if RS485 spec is 1000 meters,

gtsuport

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HI , 

I am doing on the memory adresss allocation now and i would to check whether the Wxx.xx memory can be transferred from PLC to PLC. Or should i move to D and CIO memory?

 

 

thanks a  lot.

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Looks like Serial PLC Link only works with CIO.

See attached from the manual.

CJ2M_PC_Link.pdf

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hi , 

i have some issue, I tried communication between two SCU32s. But the RXDU is not updating constantly.

I have used the below ladder diagram. Is it correct? ( the note says NO of  A202.03  AND NC of n+9 .06, but ladder is different?) No i am confused.

Also what is logical port  ( "3"in the control word#31120001 ) and what is the purpose.?

Capture1.PNG

Edited by T J SHARON

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Have you reviewed the manual for the SCU units?

CJ1W-SCU manual

The RXDU will should only update when there is new information in the serial buffer.

n+9 bit 6 in no protocol mode is the reception complete flag.  This should be a NO contact that closes when the serial buffer detects the end of string character.

A202.03 is the bit that indicates logical port 3 is available.  Logical ports allow for multiple serial communications per scan.

See image for breakdown of the control word.  You need to have the correct port on the SCU and the correct unit number.

SCU_n+9_6.jpg

RXDU_ControlWord.jpg

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thanks  a lot for the reply. 

To have a better understanding, i am adding up some more info below.

Surface rack - CPU1 ( CJ2M CPU13) + SCU32 (unit0 port1, 4 wire & terminating resistance on) 

MCP RACK - CPU2 - CPU2 ( CJ2M CPU13) + SCU32 (unit1 port1,4 wire & terminating resistance on)

Connection via 2m twister pair

Wiring, setting and program as shown  in pic.

 

SURFACE-NewProgram1-TXDU.pdf

capture.png

MCP1.PNG

MCP2.png

MCP3.PNG

SURFACE_1.PNG

SURFACE_2.png

scu32_TEST.cxp

Edited by T J SHARON

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Hi, 

I manged to establish the communication after adding a end code.

Is there any problem if i use 'FF' as start code and FE as end code.?

I can receive the data now.  but i have 2 issue now.

  1. After uploading program, need to power cycle the receiving SCU32 , then only 1534.06 works. Is it common or i miss something like restart bits? ( program remains same as previous posts)
  2. i am transmitting D100-108(D100 is DI, D101-d108 are AD) data to receiver's D2000-2008 memory (18bytes).  My analogue input  in TX side fluctuates from 0000 to 655XX if not powered, so the Received data in d2001 -d2008 follow that fluctuations. During this time some bits in  d2000  also activating, seems somthing is overriding my data.  is there any chance that d2001 data can override d2000?

THANKS A LOT 

T J SHARON

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There should not be a problem with the start and end code as long as you set up in the module.

It is not uncommon to have to cycle power after a program change.  There is a restart bit for the module.

I think you can also restart the module from CX-Programmer in the IO table.

Check the setup of the AI module.  It would appear the value is going negative.

D2001 should have no effect on D2000.  Take a look at D100 to see if it is changing.

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Hi, 

Thanks a lot for the suggestions.

1)For the ADs i used IO table to setup changed CH1-8 to enable and 0-10V in (All  voltage/current hardware dip switch set to  off). I am not sure whether any open circuit static V or anything like that. ( wiring attached, Blue color cable to 0V. A5 & B5 are NC).

2) For the data writing issue, i checked the CPU1 side D100, very stable and no issue.  But  at CPU2 side, i can see the data fluctuation in D2000 . Seems like Before transferring is ok and d2000 is overwriting only after receiving.

scu32_TEST.cxp

 

capture.png

Capture1.PNG

Edited by T J SHARON

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HI, 

I still didnt manage to get it done. 

The values are fluctuating ( like 6555**, FFF** etc) during open circuit and potentiometer is low resistance.

And values remains 0 during open circuit and potentiometer at high resistance(no fluctuation).

 

My 8 AD channels are sharing  power suppply.

DO i need connect anything to AG terminals.

Appreciate all  help and suggestions.

 

thanks

 

 

capture.png

Edited by T J SHARON

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