# Modbus/TCP integration of a new Wallbox

**URL:** <https://discourse.nodered.org/t/modbus-tcp-integration-of-a-new-wallbox/81480>\
**Category:** General\
**Created:** [21 September 2023 18:21 UTC](https://discourse.nodered.org/t/modbus-tcp-integration-of-a-new-wallbox/81480 "2023-09-21T18:21:20Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![ruffieuxh](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ruffieuxh/32/63479_2.png) [@ruffieuxh](https://discourse.nodered.org/u/ruffieuxh)\
**Post date:** [21 September 2023 18:21 UTC](https://discourse.nodered.org/t/modbus-tcp-integration-of-a-new-wallbox/81480/1 "2023-09-21T18:21:20Z")

</div>

Hi,

I successfully implemented my first Modbus/TCP Wallbox (charger for e-car) using Modbus Nodes a year ago. Now I purchased a new (simpler) one and am struggling to address it with Modbus Nodes.

I can address the new Wallbox using the TCP-In and TCP-out Nodes  
Example to query the firmware version in a function node being sent to a TCP-out node:

```auto
var abfrage = ":010300010002F9\r\n"
msg.payload = abfrage;
return msg;

```

Whereas the string, based on the interface description, means the following:  
01: The unit adress  
03: FC Read  
0001: Starting address  
0002: Number of registers  
F9: LRC (Longitudinal Redundancy Check)  
\r\n" CTRL LF

Then I get back the information in string form formated like this: \>0103020327D0 CRLF

Based on my previous experience, I am of the opinion that this should be feasible with Modbus Nodes as well - correct? But I simply do not get any answer:

```auto
[{"id":"95a66853.e78af8","type":"modbus-read","z":"be56968c.685568","name":"Read Test","topic":"ABL Read Test","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"showWarnings":true,"unitid":"1","dataType":"HoldingRegister","adr":"3","quantity":"1","rate":"1","rateUnit":"h","delayOnStart":false,"startDelayTime":"","server":"2ded7cf1.e8a884","useIOFile":false,"ioFile":"","useIOForPayload":false,"emptyMsgOnFail":true,"x":440,"y":100,"wires":[["a4ecb27f.c4415"],[]]},{"id":"2ded7cf1.e8a884","type":"modbus-client","name":"ABL","clienttype":"tcp","bufferCommands":true,"stateLogEnabled":true,"queueLogEnabled":true,"failureLogEnabled":true,"tcpHost":"192.168.1.38","tcpPort":"502","tcpType":"DEFAULT","serialPort":"/dev/ttyUSB","serialType":"RTU-BUFFERD","serialBaudrate":"9600","serialDatabits":"8","serialStopbits":"1","serialParity":"none","serialConnectionDelay":"100","serialAsciiResponseStartDelimiter":"","unit_id":"","commandDelay":1,"clientTimeout":"","reconnectOnTimeout":false,"reconnectTimeout":"","parallelUnitIdsAllowed":true}]

```

Do the Modbus Nodes calculate the LRC as well?

What am I missing?

Thanks a lot for your thoughts.

With best regards

Heinz

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [20 November 2023 18:21 UTC](https://discourse.nodered.org/t/modbus-tcp-integration-of-a-new-wallbox/81480/2 "2023-11-20T18:21:42Z")

</div>

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