@maggie How about something like this?
The Humidity/Temperature injects simulated data coming in from your sensors.
This data gets split on a semicolon:
var fields = msg.payload.trim().split(':');
msg.type = fields[0];
msg.value = parseInt(fields[1]);
return msg;
and the switch determines on msg.type where to route the data.
If you want to try this code then just copy/paste he following block into Node-Red:
[{"id":"d56d943.4bfae68","type":"switch","z":"3ce68302.c3197c","name":"","property":"type","propertyType":"msg","rules":[{"t":"cont","v":"Humidity","vt":"str"},{"t":"cont","v":"Temperature","vt":"str"},{"t":"else"}],"checkall":"true","outputs":3,"x":500.8333511352539,"y":823.6666984558105,"wires":[["7f9e7e7f.48016"],["e23d0ce6.78b9d"],["82fc1542.5faa18"]]},{"id":"68c3690d.519a88","type":"inject","z":"3ce68302.c3197c","name":"","topic":"","payload":"Humidity:45","payloadType":"str","repeat":"","crontab":"","once":false,"x":150.8333282470703,"y":807.6667022705078,"wires":[["9e7dc36.f3b074"]]},{"id":"4da4d5e4.5a276c","type":"inject","z":"3ce68302.c3197c","name":"","topic":"","payload":"Temperature:23","payloadType":"str","repeat":"","crontab":"","once":false,"x":164.3333282470703,"y":866.3333129882812,"wires":[["9e7dc36.f3b074"]]},{"id":"9e7dc36.f3b074","type":"function","z":"3ce68302.c3197c","name":"Split","func":"var fields = msg.payload.trim().split(':');\nmsg.type = fields[0];\nmsg.value = parseInt(fields[1]);\nreturn msg;","outputs":1,"noerr":0,"x":354.83333587646484,"y":824.3333625793457,"wires":[["d56d943.4bfae68"]]},{"id":"7f9e7e7f.48016","type":"debug","z":"3ce68302.c3197c","name":"Humidity","active":true,"console":"false","complete":"value","x":680.8333282470703,"y":805.0000152587891,"wires":[]},{"id":"e23d0ce6.78b9d","type":"debug","z":"3ce68302.c3197c","name":"Temperature","active":true,"console":"false","complete":"value","x":694.3333129882812,"y":852.3333129882812,"wires":[]},{"id":"82fc1542.5faa18","type":"debug","z":"3ce68302.c3197c","name":"Other","active":true,"console":"false","complete":"value","x":676.3333129882812,"y":904.3333129882812,"wires":[]}]