Hello,
i am still learning about MODBUS and created my own littile project. I read data from my pool-dosing pump and also conrtolling it via a node-red dashbaord on a VM. Its more a fun project for learning purpose.
Everything works so far but a couple uncertainties appeared in my flow (its a snipped, but it should not matter because the whole flow just reads more adresses).
In my node red dashbaord i have 6 dropdown menus, where i can make changes. This changes are send to a MQTT broker: CIM500/W_REMOTE
CIM500/W_DEAREATING (and so on)
The following flow is on a Raspi and dircetly connected to my pump to read and write to it
[
{
"id": "fbf3f9d9dd9b2d6a",
"type": "mqtt out",
"z": "36a1d1734752b2cb",
"name": "",
"topic": "CIM500/ADR_201",
"qos": "",
"retain": "",
"respTopic": "",
"contentType": "",
"userProps": "",
"correl": "",
"expiry": "",
"broker": "",
"x": 170,
"y": 320,
"wires": []
},
{
"id": "2345f538fe542fe5",
"type": "buffer-parser",
"z": "36a1d1734752b2cb",
"name": "buffer parser",
"data": "payload",
"dataType": "msg",
"specification": "spec",
"specificationType": "ui",
"items": [
{
"type": "bool",
"name": "ActRemoteAccess",
"offset": 1,
"length": 1,
"offsetbit": 0,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "ActDeaerating",
"offset": 1,
"length": 1,
"offsetbit": 1,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "AnalogueMode",
"offset": 1,
"length": 1,
"offsetbit": 2,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "ActTimerMode",
"offset": 1,
"length": 1,
"offsetbit": 3,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "ActSlowMode",
"offset": 1,
"length": 1,
"offsetbit": 4,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "ActVelocity",
"offset": 1,
"length": 1,
"offsetbit": 5,
"scale": "1",
"mask": ""
}
],
"swap1": "",
"swap2": "",
"swap3": "",
"swap1Type": "swap",
"swap2Type": "swap",
"swap3Type": "swap",
"msgProperty": "payload",
"msgPropertyType": "str",
"resultType": "keyvalue",
"resultTypeType": "return",
"multipleResult": false,
"fanOutMultipleResult": false,
"setTopic": true,
"outputs": 1,
"x": 150,
"y": 280,
"wires": [
[
"722783b55317f4f1",
"fbf3f9d9dd9b2d6a"
]
]
},
{
"id": "722783b55317f4f1",
"type": "debug",
"z": "36a1d1734752b2cb",
"name": "",
"active": false,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "payload",
"targetType": "msg",
"statusVal": "",
"statusType": "auto",
"x": 350,
"y": 280,
"wires": []
},
{
"id": "13fce020ab73d03f",
"type": "modbus-flex-getter",
"z": "36a1d1734752b2cb",
"name": "",
"showStatusActivities": false,
"showErrors": false,
"showWarnings": true,
"logIOActivities": false,
"server": "3c8dd0dd2a7c33cf",
"useIOFile": false,
"ioFile": "",
"useIOForPayload": false,
"emptyMsgOnFail": false,
"keepMsgProperties": false,
"delayOnStart": false,
"startDelayTime": "",
"x": 180,
"y": 240,
"wires": [
[
"e7535949dc228a2d",
"2345f538fe542fe5",
"bc12eea645bbc032"
],
[]
]
},
{
"id": "3b563adf71163ecf",
"type": "function",
"z": "36a1d1734752b2cb",
"name": "Read_201",
"func": "msg.payload =\n{\n value: msg.payload,\n 'fc': 3,\n 'unitid': 0,\n 'address': 200,\n 'quantity': 1\n\n};\nreturn msg",
"outputs": 1,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 150,
"y": 200,
"wires": [
[
"13fce020ab73d03f"
]
]
},
{
"id": "e7535949dc228a2d",
"type": "modbus-response",
"z": "36a1d1734752b2cb",
"name": "",
"registerShowMax": 20,
"x": 410,
"y": 180,
"wires": []
},
{
"id": "c045d0c87e79819f",
"type": "inject",
"z": "36a1d1734752b2cb",
"name": "interval",
"props": [
{
"p": "payload"
},
{
"p": "topic",
"vt": "str"
}
],
"repeat": "1",
"crontab": "",
"once": false,
"onceDelay": 0.1,
"topic": "",
"payload": "",
"payloadType": "date",
"x": 140,
"y": 160,
"wires": [
[
"3b563adf71163ecf"
]
]
},
{
"id": "bc12eea645bbc032",
"type": "function",
"z": "36a1d1734752b2cb",
"name": "Read_202",
"func": "msg.payload =\n{\n value: msg.payload,\n 'fc': 3,\n 'unitid': 0,\n 'address': 201,\n 'quantity': 1\n\n};\nreturn msg",
"outputs": 1,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 750,
"y": 200,
"wires": [
[
"60bdb194082b232c"
]
]
},
{
"id": "60bdb194082b232c",
"type": "modbus-flex-getter",
"z": "36a1d1734752b2cb",
"name": "",
"showStatusActivities": false,
"showErrors": false,
"showWarnings": true,
"logIOActivities": false,
"server": "3c8dd0dd2a7c33cf",
"useIOFile": false,
"ioFile": "",
"useIOForPayload": false,
"emptyMsgOnFail": false,
"keepMsgProperties": false,
"delayOnStart": false,
"startDelayTime": "",
"x": 780,
"y": 240,
"wires": [
[
"fa19bd3752e971ae",
"4194eec227d415c8"
],
[]
]
},
{
"id": "fa19bd3752e971ae",
"type": "modbus-response",
"z": "36a1d1734752b2cb",
"name": "",
"registerShowMax": 20,
"x": 1010,
"y": 240,
"wires": []
},
{
"id": "728b1f7ef524f8cc",
"type": "debug",
"z": "36a1d1734752b2cb",
"name": "",
"active": false,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "payload",
"targetType": "msg",
"statusVal": "",
"statusType": "auto",
"x": 950,
"y": 280,
"wires": []
},
{
"id": "4194eec227d415c8",
"type": "buffer-parser",
"z": "36a1d1734752b2cb",
"name": "buffer parser",
"data": "payload",
"dataType": "msg",
"specification": "spec",
"specificationType": "ui",
"items": [
{
"type": "bool",
"name": "ActAutoDeaerating",
"offset": 1,
"length": 1,
"offsetbit": 0,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "ActFlowControlEnable",
"offset": 1,
"length": 1,
"offsetbit": 1,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "ActModbusWatchdogEnable",
"offset": 1,
"length": 1,
"offsetbit": 2,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "ActAutoFlowAdaptEnable",
"offset": 1,
"length": 1,
"offsetbit": 3,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "ActPulseMemoryEnable",
"offset": 1,
"length": 1,
"offsetbit": 4,
"scale": "1",
"mask": ""
}
],
"swap1": "",
"swap2": "",
"swap3": "",
"swap1Type": "swap",
"swap2Type": "swap",
"swap3Type": "swap",
"msgProperty": "payload",
"msgPropertyType": "str",
"resultType": "keyvalue",
"resultTypeType": "return",
"multipleResult": false,
"fanOutMultipleResult": false,
"setTopic": true,
"outputs": 1,
"x": 750,
"y": 280,
"wires": [
[
"728b1f7ef524f8cc",
"9560f694be10b5da"
]
]
},
{
"id": "9560f694be10b5da",
"type": "mqtt out",
"z": "36a1d1734752b2cb",
"name": "",
"topic": "CIM500/ADR_202",
"qos": "",
"retain": "",
"respTopic": "",
"contentType": "",
"userProps": "",
"correl": "",
"expiry": "",
"broker": "",
"x": 770,
"y": 320,
"wires": []
},
{
"id": "ef75e27e021b43fd",
"type": "buffer-maker",
"z": "36a1d1734752b2cb",
"name": "",
"specification": "spec",
"specificationType": "ui",
"items": [
{
"name": "item",
"type": "16bitbe",
"length": 1,
"dataType": "msg",
"data": "payload"
}
],
"swap1": "",
"swap2": "",
"swap3": "",
"swap1Type": "swap",
"swap2Type": "swap",
"swap3Type": "swap",
"msgProperty": "payload",
"msgPropertyType": "str",
"x": 430,
"y": 540,
"wires": [
[
"b376463fd6e3302e"
]
]
},
{
"id": "b376463fd6e3302e",
"type": "buffer-parser",
"z": "36a1d1734752b2cb",
"name": "",
"data": "payload",
"dataType": "msg",
"specification": "spec",
"specificationType": "ui",
"items": [
{
"type": "uint16be",
"name": "decimal",
"offset": 0,
"length": 1,
"offsetbit": 0,
"scale": "1",
"mask": ""
}
],
"swap1": "",
"swap2": "",
"swap3": "",
"swap1Type": "swap",
"swap2Type": "swap",
"swap3Type": "swap",
"msgProperty": "payload",
"msgPropertyType": "str",
"resultType": "keyvalue",
"resultTypeType": "return",
"multipleResult": false,
"fanOutMultipleResult": false,
"setTopic": true,
"outputs": 1,
"x": 430,
"y": 580,
"wires": [
[
"ca2d83178b5842fc"
]
]
},
{
"id": "ca2d83178b5842fc",
"type": "function",
"z": "36a1d1734752b2cb",
"name": "write_101",
"func": "var fc = 6;\nvar sa = 100;\nvar addresses = 1;\nvar value = msg.payload.decimal; // value calculated from buffer-parser\n\nmsg.payload = { \"value\": value, 'fc': fc, 'unitid': 1, 'address': sa, 'quantity': addresses };\n\nreturn msg;",
"outputs": 1,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 420,
"y": 620,
"wires": [
[
"5dcded8496d81837",
"e43c2a1897cbf75c"
]
]
},
{
"id": "fbf4e6942e41664b",
"type": "function",
"z": "36a1d1734752b2cb",
"name": "update ContextADR100",
"func": "let ps = flow.get(\"ContextADR101\")\n\nps = [[ps.Remote_On_Off, ps.Deaerating, ps.AnalogueMode, ps.TimerMode, ps.SlowMode, ps.Velocity, false, false]]\n\nif (msg.topic === \"CIM500/W_Remote\") {\n ps[0][0] = msg.payload\n}\nelse if (msg.topic === \"CIM500/W_Deaerating\") {\n ps[0][1] = msg.payload;\n}\nelse if (msg.topic === \"CIM500/W_AnalogMode\") {\n ps[0][2] = msg.payload;\n}\nelse if (msg.topic === \"CIM500/W_TimerMode\") {\n ps[0][3] = msg.payload;\n}\nelse if (msg.topic === \"CIM500/W_SlowMode\") {\n ps[0][4] = msg.payload;\n}\nelse if (msg.topic === \"CIM500/W_Velocity\") {\n ps[0][5] = msg.payload;\n}\n\nmsg.payload = ps;\n\nreturn msg;\n\n",
"outputs": 1,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 470,
"y": 500,
"wires": [
[
"ef75e27e021b43fd"
]
]
},
{
"id": "76d68559827a49c5",
"type": "function",
"z": "36a1d1734752b2cb",
"name": "Read_101",
"func": "msg.payload =\n{\n value: msg.payload,\n 'fc': 3,\n 'unitid': 1,\n 'address': 100,\n 'quantity': 1\n\n};\nreturn msg",
"outputs": 1,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 1030,
"y": 540,
"wires": [
[
"8d205d8cc0db7c64"
]
]
},
{
"id": "627a1d67391794b3",
"type": "inject",
"z": "36a1d1734752b2cb",
"name": "",
"props": [
{
"p": "payload"
},
{
"p": "topic",
"vt": "str"
}
],
"repeat": "",
"crontab": "",
"once": true,
"onceDelay": "3",
"topic": "",
"payload": "",
"payloadType": "date",
"x": 1030,
"y": 500,
"wires": [
[
"76d68559827a49c5"
]
]
},
{
"id": "d7da7811fc270a98",
"type": "buffer-parser",
"z": "36a1d1734752b2cb",
"name": "",
"data": "payload",
"dataType": "msg",
"specification": "spec",
"specificationType": "ui",
"items": [
{
"type": "bool",
"name": "Remote_On_Off",
"offset": 1,
"length": 1,
"offsetbit": 0,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "Deaerating",
"offset": 1,
"length": 1,
"offsetbit": 1,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "AnalogueMode",
"offset": 1,
"length": 1,
"offsetbit": 2,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "TimerMode",
"offset": 1,
"length": 1,
"offsetbit": 3,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "SlowMode",
"offset": 1,
"length": 1,
"offsetbit": 4,
"scale": "1",
"mask": ""
},
{
"type": "bool",
"name": "Velocity",
"offset": 1,
"length": 1,
"offsetbit": 5,
"scale": "1",
"mask": ""
}
],
"swap1": "",
"swap2": "",
"swap3": "",
"swap1Type": "swap",
"swap2Type": "swap",
"swap3Type": "swap",
"msgProperty": "payload",
"msgPropertyType": "str",
"resultType": "keyvalue",
"resultTypeType": "return",
"multipleResult": false,
"fanOutMultipleResult": false,
"setTopic": true,
"outputs": 1,
"x": 1030,
"y": 620,
"wires": [
[
"704abbaddb6c8ae2"
]
]
},
{
"id": "704abbaddb6c8ae2",
"type": "change",
"z": "36a1d1734752b2cb",
"name": "ContextADR101",
"rules": [
{
"t": "set",
"p": "ContextADR101",
"pt": "flow",
"to": "payload",
"tot": "msg"
}
],
"action": "",
"property": "",
"from": "",
"to": "",
"reg": false,
"x": 1040,
"y": 660,
"wires": [
[]
]
},
{
"id": "075b8fdec43a80ce",
"type": "link out",
"z": "36a1d1734752b2cb",
"name": "link out 6",
"mode": "link",
"links": [
"19ed1612eccf7bb8"
],
"x": 835,
"y": 660,
"wires": []
},
{
"id": "19ed1612eccf7bb8",
"type": "link in",
"z": "36a1d1734752b2cb",
"name": "link in 6",
"links": [
"075b8fdec43a80ce"
],
"x": 855,
"y": 540,
"wires": [
[
"76d68559827a49c5"
]
]
},
{
"id": "0acf1f0892928080",
"type": "mqtt in",
"z": "36a1d1734752b2cb",
"name": "",
"topic": "CIM500/W_Remote",
"qos": "2",
"datatype": "json",
"broker": "",
"nl": false,
"rap": true,
"rh": 0,
"inputs": 0,
"x": 150,
"y": 500,
"wires": [
[
"fbf4e6942e41664b"
]
]
},
{
"id": "2893b70545622863",
"type": "mqtt in",
"z": "36a1d1734752b2cb",
"name": "",
"topic": "CIM500/W_Deaerating",
"qos": "2",
"datatype": "json",
"broker": "",
"nl": false,
"rap": true,
"rh": 0,
"inputs": 0,
"x": 140,
"y": 540,
"wires": [
[
"fbf4e6942e41664b"
]
]
},
{
"id": "63edc1f5b27fe804",
"type": "mqtt in",
"z": "36a1d1734752b2cb",
"name": "",
"topic": "CIM500/W_AnalogMode",
"qos": "2",
"datatype": "json",
"broker": "",
"nl": false,
"rap": true,
"rh": 0,
"inputs": 0,
"x": 130,
"y": 580,
"wires": [
[
"fbf4e6942e41664b"
]
]
},
{
"id": "6f1ffe595dde30a8",
"type": "mqtt in",
"z": "36a1d1734752b2cb",
"name": "",
"topic": "CIM500/W_TimerMode",
"qos": "2",
"datatype": "json",
"broker": "",
"nl": false,
"rap": true,
"rh": 0,
"inputs": 0,
"x": 140,
"y": 620,
"wires": [
[
"fbf4e6942e41664b"
]
]
},
{
"id": "ebcb7856ebe2cb50",
"type": "mqtt in",
"z": "36a1d1734752b2cb",
"name": "",
"topic": "CIM500/W_SlowMode",
"qos": "2",
"datatype": "json",
"broker": "",
"nl": false,
"rap": true,
"rh": 0,
"inputs": 0,
"x": 140,
"y": 660,
"wires": [
[
"fbf4e6942e41664b"
]
]
},
{
"id": "66f1be91f8795dd3",
"type": "mqtt in",
"z": "36a1d1734752b2cb",
"name": "",
"topic": "CIM500/W_Velocity",
"qos": "2",
"datatype": "json",
"broker": "",
"nl": false,
"rap": true,
"rh": 0,
"inputs": 0,
"x": 150,
"y": 700,
"wires": [
[
"fbf4e6942e41664b"
]
]
},
{
"id": "5dcded8496d81837",
"type": "modbus-flex-write",
"z": "36a1d1734752b2cb",
"name": "",
"showStatusActivities": true,
"showErrors": true,
"showWarnings": true,
"server": "3c8dd0dd2a7c33cf",
"emptyMsgOnFail": false,
"keepMsgProperties": false,
"delayOnStart": false,
"startDelayTime": "",
"x": 450,
"y": 660,
"wires": [
[
"075b8fdec43a80ce",
"a1c8ce5a9b7475dd"
],
[]
]
},
{
"id": "e29ff321a62aaf80",
"type": "modbus-response",
"z": "36a1d1734752b2cb",
"name": "",
"registerShowMax": 20,
"x": 1310,
"y": 580,
"wires": []
},
{
"id": "a1c8ce5a9b7475dd",
"type": "modbus-response",
"z": "36a1d1734752b2cb",
"name": "",
"registerShowMax": 20,
"x": 670,
"y": 660,
"wires": []
},
{
"id": "8d205d8cc0db7c64",
"type": "modbus-flex-getter",
"z": "36a1d1734752b2cb",
"name": "",
"showStatusActivities": true,
"showErrors": true,
"showWarnings": true,
"logIOActivities": false,
"server": "3c8dd0dd2a7c33cf",
"useIOFile": false,
"ioFile": "",
"useIOForPayload": false,
"emptyMsgOnFail": false,
"keepMsgProperties": false,
"delayOnStart": false,
"startDelayTime": "",
"x": 1060,
"y": 580,
"wires": [
[
"e29ff321a62aaf80",
"d7da7811fc270a98"
],
[]
]
},
{
"id": "e43c2a1897cbf75c",
"type": "debug",
"z": "36a1d1734752b2cb",
"name": "debug 21",
"active": false,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "false",
"statusVal": "",
"statusType": "auto",
"x": 640,
"y": 620,
"wires": []
},
{
"id": "b3fece4a99faa782",
"type": "comment",
"z": "36a1d1734752b2cb",
"name": "WRITE PROCESS",
"info": "",
"x": 150,
"y": 440,
"wires": []
},
{
"id": "e24cff856cebe718",
"type": "comment",
"z": "36a1d1734752b2cb",
"name": "READ PROCESS",
"info": "",
"x": 160,
"y": 100,
"wires": []
},
{
"id": "3c8dd0dd2a7c33cf",
"type": "modbus-client",
"name": "CIM500/Rasp",
"clienttype": "tcp",
"bufferCommands": true,
"stateLogEnabled": false,
"queueLogEnabled": false,
"failureLogEnabled": true,
"tcpHost": "192.168.1.2",
"tcpPort": "502",
"tcpType": "DEFAULT",
"serialPort": "/dev/ttyUSB",
"serialType": "RTU-BUFFERD",
"serialBaudrate": "9600",
"serialDatabits": "8",
"serialStopbits": "1",
"serialParity": "none",
"serialConnectionDelay": "100",
"serialAsciiResponseStartDelimiter": "0x3A",
"unit_id": "1",
"commandDelay": "1",
"clientTimeout": "1000",
"reconnectOnTimeout": true,
"reconnectTimeout": "2000",
"parallelUnitIdsAllowed": true,
"showWarnings": true,
"showLogs": true
}
]
-
I dont know if there is a right or wrong way to use MODBUS, but i am curious if my conecpt seems to be right
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WHat i noticed: The MODBUS FLEX WRITE has always for a split second "queue " in its node. Since i read data from my pump every second, its kinda logic to me. long story short. What i ask myself. How can i avoid (in this flow specfic right now) that there wont be any issue that the reading and writing process will disturb each other?!
Also i am happy for constructive input. Love to learn new ways
thank you
