How can I write on modbus WAGO digital outputs

[bertrand]

• Platform information:

  • Hardware: virtualbox, Wago 750-881, digital output 750-1504
  • OS: Linux Mint 19
  • Java Runtime Environment: openjdk-8-jre
  • openHAB version: 2.4

• Issue of the topic:
  No write on the output is taken into account, it seems it’s read only. On the modbus log, I can see a message is sent. When I set the output with an another system (Calaos), the state of the output is updated in habpanel.
  The solution autoupdate=“false” doesn’t work.
  Thanks for your help.

• Configurations:

  • Things configuration:

Bridge modbus:tcp:wago [ host="192.168.1.33", port=502, id=1 ] {
        Bridge poller coils [ start=512, length=16, refresh=5000, type="coil" ] {
                Thing data do0 [ readStart="512", readValueType="bit", writeStart="512", writeValueType="bit", writeType="coil" ]        
                Thing data do1 [ readStart="513", readValueType="bit", writeStart="513", writeValueType="bit", writeType="coil" ]
	        Thing data do2 [ readStart="514", readValueType="bit", writeStart="514", writeValueType="bit", writeType="coil" ]
	        Thing data do3 [ readStart="515", readValueType="bit", writeStart="515", writeValueType="bit", writeType="coil" ]
	        Thing data do4 [ readStart="516", readValueType="bit", writeStart="516", writeValueType="bit", writeType="coil" ]
	        Thing data do5 [ readStart="517", readValueType="bit", writeStart="517", writeValueType="bit", writeType="coil" ]
	        Thing data do6 [ readStart="518", readValueType="bit", writeStart="518", writeValueType="bit", writeType="coil" ]
	        Thing data do7 [ readStart="519", readValueType="bit", writeStart="519", writeValueType="bit", writeType="coil" ]
	        Thing data do8 [ readStart="520", readValueType="bit", writeStart="520", writeValueType="bit", writeType="coil" ]
	        Thing data do9 [ readStart="521", readValueType="bit", writeStart="521", writeValueType="bit", writeType="coil" ]
	        Thing data do10 [ readStart="522", readValueType="bit", writeStart="522", writeValueType="bit", writeType="coil" ]
	        Thing data do11 [ readStart="523", readValueType="bit", writeStart="523", writeValueType="bit", writeType="coil" ]
	        Thing data do12 [ readStart="524", readValueType="bit", writeStart="524", writeValueType="bit", writeType="coil" ]
	        Thing data do13 [ readStart="525", readValueType="bit", writeStart="525", writeValueType="bit", writeType="coil" ]
	        Thing data do14 [ readStart="526", readValueType="bit", writeStart="526", writeValueType="bit", writeType="coil" ]
	        Thing data do15 [ readStart="527", readValueType="bit", writeStart="527", writeValueType="bit", writeType="coil" ]
        }
}

• Items configuration:

Switch WO_4_01            "Digital Output index 0 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do0:switch" }
Switch WO_4_02            "Digital Output index 1 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do1:switch" }
Switch WO_4_03            "Digital Output index 2 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do2:switch" }
Switch WO_4_04            "Digital Output index 3 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do3:switch" }
Switch WO_4_05            "Digital Output index 4 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do4:switch" }
Switch WO_4_06            "Digital Output index 5 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do5:switch" }
Switch WO_4_07            "Digital Output index 6 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do6:switch" }
Switch WO_4_08            "Digital Output index 7 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do7:switch" }
Switch WO_4_09            "Digital Output index 8 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do8:switch" }
Switch WO_4_10            "Digital Output index 9 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do9:switch" }
Switch WO_4_11            "Digital Output index 10 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do10:switch" }
Switch WO_4_12            "Digital Output index 11 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do11:switch" }
Switch WO_4_13            "Digital Output index 12 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do12:switch" }
Switch WO_4_14            "Digital Output index 13 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do13:switch" }
Switch WO_4_15            "Digital Output index 14 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do14:switch" }
Switch WO_4_16            "Digital Output index 15 [%d]"  (Wago_output_4)  { channel="modbus:data:wago:coils:do15:switch" }

• Logs modbus:

2019-07-31 14:32:21.598 [DEBUG] [rt.modbus.internal.ModbusManagerImpl] - Scheduling one-off write task BasicWriteTask@521e6645[request=BasicModbusWriteCoilRequestBlueprint@4445e674[slaveId=1,reference=522,functionCode=WRITE_COIL,bits=SingleBitArray(bit=1),maxTries=3],endpoint=ModbusTCPSlaveEndpoint@4b5a371c[address=192.168.1.33,port=502],callback=org.openhab.binding.modbus.internal.handler.ModbusDataThingHandler@77857b0f]
2019-07-31 14:32:21.599 [DEBUG] [rt.modbus.internal.ModbusManagerImpl] - Will now execute one-off write task BasicWriteTask@521e6645[request=BasicModbusWriteCoilRequestBlueprint@4445e674[slaveId=1,reference=522,functionCode=WRITE_COIL,bits=SingleBitArray(bit=1),maxTries=3],endpoint=ModbusTCPSlaveEndpoint@4b5a371c[address=192.168.1.33,port=502],callback=org.openhab.binding.modbus.internal.handler.ModbusDataThingHandler@77857b0f], waited in thread pool for 1
2019-07-31 14:32:21.600 [DEBUG] [wimpi.modbus.net.TCPMasterConnection] - connect()
2019-07-31 14:32:21.661 [DEBUG] [ernal.handler.ModbusDataThingHandler] - Successful write, matching request BasicModbusWriteCoilRequestBlueprint@4445e674[slaveId=1,reference=522,functionCode=WRITE_COIL,bits=SingleBitArray(bit=1),maxTries=3]
2019-07-31 14:32:21.663 [DEBUG] [rt.modbus.internal.ModbusManagerImpl] - Modbus operation ended, timing info: {total: 64 ms, connection: 24, transaction=39, callback=1} [operation ID 5f64aac3-b23d-42c8-ad8d-00c420627481]

[rossko57]

There is no poller Thing in your Modbus things configuration.

Oddly, I don’t think that will stop it writing to Modbus - but you would never read back any results.

[bertrand]

Thanks for this remark, I deleted this line with the comment.
The post is corrected.

[rossko57]

Other people use WAGO 750-881 with openHAB, so stick with it.

One thing I do notice from previous threads, is that the WAGO usually expects read and write to different addresses. I don’t know why or have any idea about how to set the WAGO up.
Example -

Modbus binding: resend values to device after power down

Hello, I’ve got some issues getting the combination of my Wago PLC 750-881 working stable via modbus. When everything stays online, everything works perfect. The problem arises when my PLC is powered off. When OpenHab server keeps running and I turn off my PLC, the modbus coils are not set again in the PLC when the PLC is running again. (they are ON in OpenHab, but not TRUE again in PLC). I’m running openHAB 2.4.0 Release Build with the Modbus Binding on Ubuntu. Below my config: modbus.thi…

@bertrand

When I set the output with an another system (Calaos), the state of the output is updated in habpanel.

What would be most useful here is - what does that other system send and to where?

[RobbeM (Robbe)]

You can check my topic Modbus binding: resend values to device after power down and i’m sure you will get it working as i think everything is explained there in the last post.

In the wago PLC, I use M bits to control the outputs.
That way I can control the outputs via PLC or OpenHab.
In the PLC it looks like this:
output := (modbus bit OR PLC bit)

If you have anymore questions just ask and I will try to check my configuration again and give more info.

[bertrand]

Good evening !
I think I programed everything fine in CodeSys.
I can read the digital input, i can write %MX0.0, but when I want to write de digital output, it doesn’t work.
I can force the ouput to true in CodeSys when online.

Variables :

VAR
    mb_con_bit_00 		AT %MX0.0: BOOL;
    DI_1_00 AT %IX0.0 : BOOL;
    DO_1_00 AT %QX0.0 : BOOL;
END VAR

PLC_PRG :

DO_1_00:= DI_1_00;

all the same with this :

DO_1_00:= mb_con_bit_00;

Thanks for your help.

[RobbeM (Robbe)]

Do you have both these statements

DO_1_00:= DI_1_00;

DO_1_00:= mb_con_bit_00;

Below each other in the PLC?
If so, the last statement always overrules the first statement.
So please check that first.

[bertrand]

I tried with the first statement only and after I tried with the second statement. Not both at the same time.

[RobbeM (Robbe)]

If you have

DO_1_00:= mb_con_bit_00;

and force mb_con_bit_00 to TRUE in the PLC, the output becomes active right?

If I look at your configuration, your start address might be wrong.
Below you can find my working config.

Wago is actually quite simple regarding modbus.
Inputs bits are mapped to a certain modbus address range, output bits to another range,
input words, output words, flags, flagwords, … they are all mapped to a certain modbus address range.
You should check the manual for this.

When you get the start address, you need to calculate the address you actually need in your config.
Below I show you how to calculate the address for MX600.0 and so on.

Things:

    //Controlbits to be set from OpenHab
    //In the PLC these are located at MW600-M699 = 99*16=1584 control bits
    //Modbus starta ddress for bits: MX0.0 starts at modbus address12288.
    //600 words * 16 bits => +9600 ==> So modbus start address: 21888
    Bridge poller wagooutputscon [ start=21888, length=1024, refresh=100, type="coil" ] {
        Thing data mb_con_bit_0 [ writeStart="21888", writeValueType="bit", writeType="coil"]
        Thing data mb_con_bit_1 [ writeStart="21889", writeValueType="bit", writeType="coil"]
        Thing data mb_con_bit_2 [ writeStart="21890", writeValueType="bit", writeType="coil"]
        Thing data mb_con_bit_3 [ writeStart="21891", writeValueType="bit", writeType="coil"]
        Thing data mb_con_bit_4 [ writeStart="21892", writeValueType="bit", writeType="coil"]
        Thing data mb_con_bit_5 [ writeStart="21893", writeValueType="bit", writeType="coil"]
        Thing data mb_con_bit_6 [ writeStart="21894", writeValueType="bit", writeType="coil"]
        Thing data mb_con_bit_7 [ writeStart="21895", writeValueType="bit", writeType="coil"]
    }

Items:

Switch mb_con_bit_0 "mb_con_bit_0" {channel="modbus:data:wago:wagooutputscon:mb_con_bit_0:switch", autopudate="false"}
Switch mb_con_bit_1 "mb_con_bit_1" {channel="modbus:data:wago:wagooutputscon:mb_con_bit_1:switch", autopudate="false"}
Switch mb_con_bit_2 "mb_con_bit_2" {channel="modbus:data:wago:wagooutputscon:mb_con_bit_2:switch", autopudate="false"}
Switch mb_con_bit_3 "mb_con_bit_3" {channel="modbus:data:wago:wagooutputscon:mb_con_bit_3:switch", autopudate="false"}

Variable declaration in Wago PLC:

	(*Digital control via modbus (%MW600-M699 = 99*16=1584 controle bits)		*)
	(*#Modbus startadres voor bits: MX0.0 start op modbus adres 12288.			*)
	(*600 woorden * 16 bits => +9600 ==> Dus modbus startadres: 21888			*)
	(*Used to change state of outputs											*)
	mb_con_bit_0 		AT %MX600.0: BOOL := FALSE;		(*Adres 21888*)
	mb_con_bit_1 		AT %MX600.1: BOOL := FALSE;		(*Adres 21889*)
	mb_con_bit_2 		AT %MX600.2: BOOL := FALSE;		(*Adres 21890*)
	mb_con_bit_3 		AT %MX600.3: BOOL := FALSE;		(*Adres 21891*)
	mb_con_bit_4 		AT %MX600.4: BOOL := FALSE;		(*Adres 21892*)
	mb_con_bit_5 		AT %MX600.5: BOOL := FALSE;		(*Adres 21893*)
	mb_con_bit_6 		AT %MX600.6: BOOL := FALSE;		(*Adres 21894*)
	mb_con_bit_7 		AT %MX600.7: BOOL := FALSE;		(*Adres 21895*)

Code in Wago PLC:

(*Uitgangen Leefruimte*)
uitgang0:=mb_con_bit_0;
uitgang1:=mb_con_bit_1;
uitgang2:=mb_con_bit_2;
uitgang3:=mb_con_bit_3;

You want to use MX0.0, so that starts at modbus address 12288 instead of 512.

Also one thing you could check, I declared my MX600.0 and so on as a GLOBAL VARIABLE.
I’m not sure if it’s important but you could try that too if it doesn’t work.