Twido EXCH & MSG functions

[Greg 0]

Hi guys, can anybody explain the values that written in the application to retrieve data from modbus slaves through the Ethernet port, i read a little bit from the help of TwidoSuite i understood all the concept of getting the data, the only thing i still don't understand the first 4 raws with that values as it explained in the examples in Hex, and why does it changes all the time. and how can i determine from which addresses i would like to get the data from the slave? please see attached example of code as described in help. Thanks in advance, Best Regards, Greg.

[Greg 0]

anyone help?

[aggattapauer 2]

priviet LD1 [%MW0;=16#0106] 01 SEND/RECEIVE 06 NUMBER OF BYTES OF THE MODBUS STRING [%MW1;=16#0300] 03 OFFSET (ANSWER) 00 OFFSET (TRANSMISSION) [%MW2;=16#0103] 01 SLAVE ADDRESS 03 READING WORDS [%MW3;=16#0000] 0000 START ADDRESS [%MW4;=16#0004] 0004 NUMBER OF WORDS TO READ LD1 AND %MSG2.D [EXCH2 %MW0:11] FROM MW0 TO MW4 TRANSMISSION + MW5 TO MW10 ANSWER THE ANSWER WILL BE: %MW5 = 16#0103 ECHO OF THE FIRST WORD TRANSMITTED %MW6 = 16#0008 00 BYTE ADDED (OFFSET = 3RD BYTE OF THE ANSWER) 08 NUMBER OF BYTES OF DATA IN THE ANSWER %MW7 = 16#XXXX FIRST WORD %MW8 = 16#YYYY SECOND WORD %MW9 = 16#ZZZZ THIRD WORD %MW10 = 16#WWWW FOURTH WORD

[Greg 0]

Hi aggattapauer, Thanks a lot, couldn't get better answer then that, appreciate it a lot. Could you tell me please where did you get this info from? And where can i find all the parameters i can write into the first words? Best Regards, Greg. Edited 18 Oct 2011 by Greg

[Greg 0]

Hi, again i wanted to thank you, i found the whole explanation in programming manual of twidosuite. Best Regards, Greg.

[RichardK 0]

On 10/17/2011 at 6:18 AM, aggattapauer said:

priviet LD1 [%MW0;=16#0106] 01 SEND/RECEIVE 06 NUMBER OF BYTES OF THE MODBUS STRING [%MW1;=16#0300] 03 OFFSET (ANSWER) 00 OFFSET (TRANSMISSION) [%MW2;=16#0103] 01 SLAVE ADDRESS 03 READING WORDS [%MW3;=16#0000] 0000 START ADDRESS [%MW4;=16#0004] 0004 NUMBER OF WORDS TO READ LD1 AND %MSG2.D [EXCH2 %MW0:11] FROM MW0 TO MW4 TRANSMISSION + MW5 TO MW10 ANSWER THE ANSWER WILL BE: %MW5 = 16#0103 ECHO OF THE FIRST WORD TRANSMITTED %MW6 = 16#0008 00 BYTE ADDED (OFFSET = 3RD BYTE OF THE ANSWER) 08 NUMBER OF BYTES OF DATA IN THE ANSWER %MW7 = 16#XXXX FIRST WORD %MW8 = 16#YYYY SECOND WORD %MW9 = 16#ZZZZ THIRD WORD %MW10 = 16#WWWW FOURTH WORD

This explanation helped me too, I followed up and can read (read only) registers of one soft starter. I tried to read registers of four soft starters using a M221 PLC but I can't! Please would you explain me on these MSG1/2 to read all the soft starters' registers. Attached is how I wrote to read read 11 registers of a soft starter.

Thank you in advance  

Edited 8 Dec 2021 by RichardK

[Wasan 72]

@RichardK Which softstarter brand and model do you use and how ti communicate with it (TCP, Modbus or anything)?

Could you send your softstarter communication manual to us?

[RichardK 0]

@WasanThanks Wasan, attached is the comms manual

WEG-ssw06-serial-communication-manual-0899.5731-1.6x-manual-english.pdf

Edited 15 Dec 2021 by RichardK

[Wasan 72]

@RichardK I have check on SoftStarter Manual it use Modbus RTU Protocol that can use READ_VAR function on M221 that easier than EXCH/MSG command.

Could you tell us which 11 parameters to read and what Device ID for four softstarters?

And send us program for EXCH/MSG because attach files are so blur to read.

[RichardK 0]

@Wasan Thank you, actually 12 registers, Register 3 to 14 (Motor Current to Soft starter fault codes). I was using timers to read two soft starters. Instead of this EXCH/MSG please help me how to use this READ_VAR. Attached is my PLC program and the list of registers to read.

 

Thank you once again for help

Chapter 6.pdf

MY PLC PROGRAM.pdf

[Wasan 72]

Hi @RichardK

I have create example program for READ_VAR function block attacth to this post

I don't have real hardware then I'm not sure that it will work correctly.

Then I will describe how program works

1. Create program on SoMachine or Machine Expert - Basic then assign communication parameter on PLC serial port to match with Soft Starter Parameter.

2. Config Modbus parameter to set PLC as Modbus Master.

3. In this program I have use system clock 100 ms %S5 to count uo conuter for each READ_VAR command for this project I use 4 device to read then I set preset to be 4 + 1 = 5 when counter reach preset it will reset automatically.

4. use compare block for %C0.V (Counter 0 Current Value) = 1 when counter reach 1 it will operate then put %READ_VAR function block after it at EXECUTE pin

You need to assign %READ_VARX for each communication block. Example I start with %READ_VAR0 for communicate with device slave ID 1.

Detail for configuration shown below

Link: Which PLC port to connect with Modbus Device

Id : Modbus Slave ID for SoftStarter

TimeOut : How long to timeout after wait for resplonse

ObjType : Function code that you use (use 0 For Modbus 0x03 for read multiple registers)

FirstObj : First Register to be read (For this softstarter start with 0 for P000 then we need to read P003 that means we start with 3)

Quantity : How many data to read (use 12 for P003 - P014)

IndexData : First %MW to recieve data (For this block use %MW0 - %MW11 to recieve 

5. Then create similar program for each device to read by add compare value to 1 for each command and change %READ_VAR0 to next %READ_VAR1..2..3 and config IndexData for each READ_VARX function block. 

6. Then we will end at %READ_VAR3 for device 4.

Now we can read Modbus data from 4 softstarters P003 - P014 as these

No.1 -> %MW0 - %MW11

No.2 -> %MW20 - %MW31

No.3 -> %MW40 - %MW51

No.4 -> %MW60 - %MW71

MrPLC_ReadVar_SoftStarter_01.smbp

[RichardK 0]

@Wasan Thank you very much for help Wasan! I will follow this.

[RichardK 0]

@Wasan I followed the example you gave, it is perfectly reading the four soft starters.

 

I was also trying to read and write between M221 PLC using the Read_Var/ Write_Var via network (3_eth1 not 1_SL1) but I still cannot get it right, every time I try, I still make wrong setting somewhere, please help me.

 

Thank you

[Wasan 72]

@RichardK Which device model that you need to connect with Modbus TCP?

[RichardK 0]

 

@Wasan5 x M221CE24T PLC CONTROLLERS (1 MASTER AND FOUR SLAVES), I tried and got them finally communicating through our network but one problem, when one of them goes offline/power off, the entire communication fails. Though four of them online they still cannot communicate with master until the one goes off comes back online. How can I make master communicate separately with its slaves and I can identify which slave goes off. Attached is the PLC Program of the master Controller (M221CE24T)

 

Thank you

 

MASTER PLC_10.190.153.232.smbp

Edited 31 Dec 2021 by RichardK

[RichardK 0]

@Wasan Good day Wasan, I tried to use the same setup of the Example you gave on the Read_Var to read registers of four Toshiba Softstaters (Manual link:  http://sunnice.com/manuals/(71105)%20Toshiba%20TMS7%20Users%20Manual.pdf) but cannot read anything from the Soft starters. The Toshiba Softstaters' RS485 port can only communicate on MODBUS ASCII, I tried to change the PLC Serial Link settings to MODBUS ASCII but still cannot, How can I configure Modbus ASCII on my M221 PLC (SoMachine Software)?

 

Than you

[Wasan 72]

@RichardK I have never use Modbus ASCII on M221 but I think if change protocol on communication setting it should be fine to use READ_VAR maybe wait for other to clarify with these.

[RichardK 0]

@Wasan Good day Wasan, in a M221 PLC program I am using a counter and I must make sure the last counted value is remembered during power outages. Where can I put this system bit 1 (%S1) in a rung to do this? I search in the M221 Help but can't find any, just descriptions only. Please show me where to use this system bit.

 

Thank you

Edited 20 Feb 2022 by RichardK