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nasir_ash

CQM1H -SCB41

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Dear Friends can any boody help HOW to communicate rs485 with 3g3jx inverter. first time i am going to do it. need a brief answer. regards NASIR

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I love it!

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dear team please help on the issue. you guys enjoying it? regards NASIR

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You got what you asked... unless brief was not what you meant?

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They are correct of course. Modbus is the communication protocol to be used. It is too bad that you are not using a CP1 or a CJ PLC. This would be easy (CP1 PLCs have Easy Modbus built in and there are Modbus protocol macros written and available for the CJ PLC). With a CQM1H, this becomes a bit more difficult. You will have to implement Modbus using TXD and RXD commands. I have not seen any sample code for this, so it would be a matter of writing your own code. Good luck. Edited by Michael Walsh

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Dear friends BRIEF mean detailed help is required. However i am sorry that i dont have Cj and CP1 plcs right now. i have to do job on cqm1h as cqm1h have SCB 41 card installed on it and manual says that protocol macro can be supported by this card. but CX-Protocol does nt have option for CQM1H, i seen some other place they communicate CPM2*-40cdr with inverters via Pheriphral port with a CIF01. i want to communicate CQM1H with RS485/422 port with inverters. for this i need your help with some example. regards NASIR

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He's got a protocol macro capable port. The CQM1H uses C200H Protocol Macros. Here is a very simple PMCr that you can use to start your own for the CQm1H. Modbus RTU Master.zip

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Dear Jay thanks for your help. i will try it, come back to you if face any problem. Thanks to all the guys who contribute on this issue. regards NASIR

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You know, I had it in the back of my mind that the CQM1H supported PMCR. So for a quick check, I looked to see if the CQM1H could be added to a CX-Protocol project and when it could not, I did not investigate any further....I guess I should have trusted my instincts.

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Hey, man! You just keep all that motion stuff at the front of your brain. We need resources like you for other things than ancient history.

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Dear Jay Now i am trying to read "SINGLE OUPUT REGISTER PROTOCOL #703" follwoing your last attahced file. transfer the Psw file via Cx-protocol to scb41 card. Now the problem is that i am still unable to get the data from invereter. setting whcih i made on INVERTER are as: 9600, 8, E, 2. node address is 2. port #2 of communication card is configured on 9600, 8,E, 2, protocol macro. configured the PMCR as dm120 dm121 , dm 122 , dm123 , dm125 2703h 0004h , 0002h , 0001h , 0002h but gettig no feed back from the inverter. please find the attahced file screen shot of the 3g3jx inverter "READING COIL" please suggets what need to do more. regards NASIR

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Check the following: 1. Normally Modbus is 9600, 8, N, 1 2. Check wiring and report back with details. 3. Do you have any ladder triggering the Protocol Macro? Report back details. 4. Have you run a trace on the comms? Report back details. 5. What register are you trying to read in the inverter? Report back details.

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Dear Jay please find the answers in blue. 1. Normally Modbus is 9600, 8, N, 1 Changed the settinng to 9600, 8,N,1 2. Check wiring and report back with details. For wiring please find the attahced picture. 3. Do you have any ladder triggering the Protocol Macro? Report back details. Please find the attahced ladder program 4. Have you run a trace on the comms? Report back details. When tracing starts, showing continious tracing, but when stopped and uplaod nothing is observed. or no trace is found. (picture attahced.) 5. What register are you trying to read in the inverter? Report back details. i am trying to set single bit ON/ OFF, calling protocol #705, (attached writing coil) please also find the attached register list i am feeling that the in the memory table i am not writing the correct sequence of command. please have a look and help. regards NASIR testing modbus.cxp

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Right. And how are we supposed to check the operands of the PMCR instruction if you use DM words for them?

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Right. And how are we supposed to check the operands of the PMCR instruction if you use DM words for them? Dear PDL you can see them by opening the dm table, which i saved in the project. for you: Dm120 2705 port #2 , sequence # 705 Dm121 Dm122 Dm123 Dm124 No of word: 04, node address: 01, Hex Bit:05 (function code for 3g3jx writing in to COIL) , Set Bit ON: FF00 0004 0001 0005 FF00 Dm140 Respose word 0006 6 word response regards NASIR

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My bad, I jumped that one too quickly. You could have mentioned though. I will check the operands and get back to you.

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Looking at your code, here's a few things I would try/check. - Are you 100% sure the DM values in the project memory are loaded in the PLC? I would load the values using MOV instructions so you can clearly check/ modify easily. - Perform a settings upload of the Serial B port settings to verify the settings are truly loaded. - You need to put a NC contact of the PCMR execution flag of port 2 ( IR207.12 ) in the branch that fires the instruction to be sure the instruction is only executed when the Protocol Macro finished executing. - I think the response size is 2 instead of 6 words but that should not be the problem. - Double check inverter serial parameters (slave ID, baud, parity etc) and set control mode and speed reference method parameters to serial. Make sure you power cycled the inverter after setting these parameters. It should display CALL or CE when communications timeout. Good luck. A few other things that pop my mind: - Make sure the 2/4 wire switch on SCB is set correctly. - If you don't see the comms led flicker on the SCB, look for the cause in the PLC. Else look outside the PLC.

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Couldn't have said it better. Let's see the results of your suggestions. The PMCR ladder is obviously not being executed for the trace should show the outgoing command.

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Never really used the trace option much. Now that I look at the picture, isn't port 1 > B and port 2 > A? I recall there was something unlogical with the port numbers/letters.

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It depends on what SCU you are using. I bow to whatever PMCR has to say.

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Dear PDL and Jay please find the answers in Blue: please find tha attahced program. using mov instruction serial board scb41, port #2 (Rs422/485) picture attached. IR 207.12 is ON and when bit 20.00 ON, Comm#2 lit blinks and OFF, then 207.12 OFF and doesnt turn ON again. PCMR i am using please find it. please find the attached trace. please suggest regards NASIR Modbus_RTU_Master one seq705.zip testing modbus.cxp Edited by nasir_ash

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At this stage I would check section 5-6 "5-6 Control Bits, Flags, and Status Information" and section 9 "SECTION 9 Troubleshooting and Maintenance" of the SCB manual. See if they can tell you what's wrong. *edit* I see you stripped the Protocol Macro down to just sequence 705. I don't think we covered this yet but have you done a protcol compare/upload to verify the protocol has been correctly loaded in the SCB?

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Dear Pdl please review my last reply again. now i am getting the trace. when edit the PMCR with seq 705 and 705 only it transfered to SCB sucessfully and verified sucessfully. as per trace i am not getting the response. please have a look again and suggest. regards NASIR

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