Do these payload values look right?
Demo flow...
[{"id":"3cdc61d2.9d548e","type":"inject","z":"f77cda4d.5d7628","name":"go","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":1050,"y":80,"wires":[["7d72ded.8fbf02"]]},{"id":"7d72ded.8fbf02","type":"function","z":"f77cda4d.5d7628","name":"modbus msg","func":"\nreturn { \"settings\": { \"name\": \"Solax\", \"topic\": \"Solax\", \"adr\": \"0\", \"quantity\": \"126\", \"dataType\": \"InputRegister\", \"ieeeType\": \"off\", \"ieeeBE\": true, \"timerID\": { \"_idleTimeout\": 5000, \"_idlePrev\": { \"_idleNext\": \"[Circular ~.settings.timerID]\", \"_idlePrev\": { \"_idleTimeout\": 5000, \"_idlePrev\": { \"_idleTimeout\": 5000, \"_idlePrev\": { \"_idleTimeout\": 5000, \"_idlePrev\": { \"_idleTimeout\": 5000, \"_idlePrev\": { \"_idleTimeout\": 5000, \"_idlePrev\": { \"_idleTimeout\": 5000, \"_idlePrev\": \"[Circular ~.settings.timerID]\", \"_idleNext\": \"[Circular ~.settings.timerID._idlePrev._idlePrev._idlePrev._idlePrev._idlePrev._idlePrev]\", \"_idleStart\": 43475234, \"_repeat\": null, \"_destroyed\": false }, \"_idleNext\": \"[Circular ~.settings.timerID._idlePrev._idlePrev._idlePrev._idlePrev._idlePrev]\", \"_idleStart\": 43475233, \"_repeat\": null, \"_destroyed\": false }, \"_idleNext\": \"[Circular ~.settings.timerID._idlePrev._idlePrev._idlePrev._idlePrev]\", \"_idleStart\": 43475232, \"_repeat\": null, \"_destroyed\": false }, \"_idleNext\": \"[Circular ~.settings.timerID._idlePrev._idlePrev._idlePrev]\", \"_idleStart\": 43475231, \"_repeat\": null, \"_destroyed\": false }, \"_idleNext\": \"[Circular ~.settings.timerID._idlePrev._idlePrev]\", \"_idleStart\": 43475230, \"_repeat\": null, \"_destroyed\": false }, \"_idleNext\": \"[Circular ~.settings.timerID._idlePrev]\", \"_idleStart\": 43475229, \"_repeat\": null, \"_destroyed\": false }, \"expiry\": 43480229, \"id\": -9007199254620531, \"msecs\": 5000, \"priorityQueuePosition\": 17 }, \"_idleNext\": { \"_idleTimeout\": 5000, \"_idlePrev\": \"[Circular ~.settings.timerID]\", \"_idleNext\": { \"_idleTimeout\": 5000, \"_idlePrev\": \"[Circular ~.settings.timerID._idleNext]\", \"_idleNext\": { \"_idleTimeout\": 5000, \"_idlePrev\": \"[Circular ~.settings.timerID._idleNext._idleNext]\", \"_idleNext\": { \"_idleTimeout\": 5000, \"_idlePrev\": \"[Circular ~.settings.timerID._idleNext._idleNext._idleNext]\", \"_idleNext\": { \"_idleTimeout\": 5000, \"_idlePrev\": \"[Circular ~.settings.timerID._idleNext._idleNext._idleNext._idleNext]\", \"_idleNext\": { \"_idleTimeout\": 5000, \"_idlePrev\": \"[Circular ~.settings.timerID._idleNext._idleNext._idleNext._idleNext._idleNext]\", \"_idleNext\": { \"_idleNext\": \"[Circular ~.settings.timerID]\", \"_idlePrev\": \"[Circular ~.settings.timerID._idleNext._idleNext._idleNext._idleNext._idleNext._idleNext]\", \"expiry\": 43480229, \"id\": -9007199254620531, \"msecs\": 5000, \"priorityQueuePosition\": 17 }, \"_idleStart\": 43475229, \"_repeat\": null, \"_destroyed\": false }, \"_idleStart\": 43475230, \"_repeat\": null, \"_destroyed\": false }, \"_idleStart\": 43475231, \"_repeat\": null, \"_destroyed\": false }, \"_idleStart\": 43475232, \"_repeat\": null, \"_destroyed\": false }, \"_idleStart\": 43475233, \"_repeat\": null, \"_destroyed\": false }, \"_idleStart\": 43475234, \"_repeat\": null, \"_destroyed\": false }, \"_idleStart\": 43479503, \"_repeat\": 5000, \"_destroyed\": false } }, \"topic\": \"Solax\", \"payload\": [0, 0, 0, 2841, 2239, 0, 0, 0, 40, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4781, 0, 65509, 1, 18, 0, 0, 0, 96, 3465, 0, 0, 8, 4598, 0, 0, 124, 350, 0, 0, 5, 124, 0, 96, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 53, 0, 56055, 0, 0, 0, 0, 5000, 0, 0, 19, 0, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 7506, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2312, 0, 1, 17, 2310, 0, 0, 18], \"_msgid\": \"55713a82.52b914\" };","outputs":1,"noerr":0,"initialize":"","finalize":"","x":1050,"y":140,"wires":[["f5192783.22df58","ac96e26c.05cc4"]]},{"id":"f5192783.22df58","type":"buffer-parser","z":"f77cda4d.5d7628","name":"","data":"payload","dataType":"msg","specification":"spec","specificationType":"ui","items":[{"type":"uint16be","name":"Grid_Voltage","offset":0,"length":1,"offsetbit":0,"scale":"/ 10.0","mask":""},{"type":"int16be","name":"Grid_Current","offset":2,"length":1,"offsetbit":0,"scale":"/ 10.0","mask":""},{"type":"int16be","name":"Inverter_Power","offset":4,"length":1,"offsetbit":0,"scale":"1","mask":""},{"type":"uint16be","name":"PV1_Voltage","offset":6,"length":1,"offsetbit":0,"scale":"/ 10.0","mask":""},{"type":"uint16be","name":"PV2_Voltage","offset":8,"length":1,"offsetbit":0,"scale":"/ 10.0","mask":""},{"type":"uint16be","name":"PV3_Voltage","offset":10,"length":1,"offsetbit":0,"scale":"/ 10.0","mask":""},{"type":"uint16be","name":"PV4_Voltage","offset":12,"length":1,"offsetbit":0,"scale":"/ 10.0","mask":""},{"type":"uint16be","name":"Grid_Frequency","offset":14,"length":1,"offsetbit":0,"scale":"/ 10.0","mask":""},{"type":"int16be","name":"Battery_Voltage","offset":40,"length":1,"offsetbit":0,"scale":"/ 100.0","mask":""},{"type":"int16be","name":"Battery_Current","offset":42,"length":1,"offsetbit":0,"scale":"/ 100.0","mask":""},{"type":"int16be","name":"Battery_Power","offset":44,"length":1,"offsetbit":0,"scale":"1","mask":""}],"swap1":"","swap2":"","swap3":"","swap1Type":"swap","swap2Type":"swap","swap3Type":"swap","msgProperty":"payload","msgPropertyType":"str","resultType":"keyvalue","resultTypeType":"output","multipleResult":false,"fanOutMultipleResult":false,"setTopic":true,"outputs":1,"x":1060,"y":200,"wires":[["34d018b4.528008"]]},{"id":"ac96e26c.05cc4","type":"debug","z":"f77cda4d.5d7628","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":1230,"y":140,"wires":[]},{"id":"34d018b4.528008","type":"debug","z":"f77cda4d.5d7628","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":1230,"y":200,"wires":[]}]