Inject dynamic variables in s7 nodes

KarolisL · 20 February 2025 20:00

Long story short - not possible with current s7 nodes.
Only option is to use npm package nodes7.
Check this first:

TCP ECCONRESET

opened 08:03PM - 06 Oct 22 UTC

Hey! I'm working with your node on node-red for reading from a plc S7-1200, rack… 0 and slot 1 with external functions. But every time I send a readAllItems I get the response I want but the connection resets every time and never closes, even with dropConnection and connectionCleanup... I've been trying to solve it for a few days now, if anyone has any ideas... ```javascript var devices = msg.payload; // devices example: {"delta":0,"name":"10.255.3.214","rack":0,"slot":1,"data":"Q0.0","ip":"10.255.3.214","port":102} msg = []; let nodes7 = global.get('nodes7'); var conn = new nodes7({ globalTimeout: 2000 }); var doneReading = false; devices.forEach((/** @type {{ modbus_id: any; modbus_ip: any; modbus_port: any; address: any; quantity: any; }} */ dev) => { var variables = { DATA: dev.data }; conn.initiateConnection({ port: dev.port, host: dev.ip, rack: dev.rack, slot: dev.slot, debug: false }, connected); function connected(err) { if (typeof (err) !== "undefined") { // PLC FORA DO ALCANCE //console.log(err); node.error({ "ip": dev.ip, "port": dev.port, "message": "ERRO! Falha na leitura do host " + dev.ip + "!", "error": err.code }); flow.set("aguarda", false); conn.dropConnection(); conn.connectionCleanup(); } conn.setTranslationCB(function (tag) { return variables[tag]; }); conn.addItems('DATA'); conn.readAllItems(valuesReady); } function valuesReady(anythingBad, values) { if (anythingBad) { console.log("ERRO! Falha na leitura do host."); flow.set("aguarda", false); conn.dropConnection(); conn.connectionCleanup(); } //console.log(values); if (values.DATA != "BAD 255") { node.send({ "topic": "TCP Response", "host": dev.ip, "port": dev.port, "rack": dev.rack, "slot": dev.slot, "data": dev.data, "payload": values.DATA }); } doneReading = true; conn.dropConnection(); conn.connectionCleanup(); } }); return msg; ```

My own examples:

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Inject dynamic variables in s7 nodes

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