I'm not sure the split node would help in this instance as that will just turn it into two messages. You may be better using a simple function node to split the string into two parts (say topic and payload - then use the switch based on topic. If you import the flow below and look inside the function I think you will see what is going on.
Here is a quick flow to show what I mean
[{"id":"e0e8a0c7.ba5e2","type":"inject","z":"c4f68fc3.2dd88","name":"","topic":"","payload":"200 13264","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":140,"y":780,"wires":[["f0838f38.18818"]]},{"id":"1f5f1ed8.8427b1","type":"inject","z":"c4f68fc3.2dd88","name":"","topic":"","payload":"202 16441","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":140,"y":820,"wires":[["f0838f38.18818"]]},{"id":"91e55004.35a31","type":"inject","z":"c4f68fc3.2dd88","name":"","topic":"","payload":"200 13268","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":140,"y":860,"wires":[["f0838f38.18818"]]},{"id":"f0838f38.18818","type":"function","z":"c4f68fc3.2dd88","name":"","func":"var parts = msg.payload.split(\" \");\nmsg.topic = parts[0];\nmsg.payload = Number(parts[1]);\nreturn msg;","outputs":1,"noerr":0,"x":360,"y":820,"wires":[["b45e3838.284418"]]},{"id":"b45e3838.284418","type":"switch","z":"c4f68fc3.2dd88","name":"","property":"topic","propertyType":"msg","rules":[{"t":"eq","v":"200","vt":"str"},{"t":"eq","v":"202","vt":"str"},{"t":"else"}],"checkall":"true","repair":false,"outputs":3,"x":530,"y":820,"wires":[["cbc6e6f8.dd8c28"],["6822e7f9.3973c8"],[]]},{"id":"cbc6e6f8.dd8c28","type":"debug","z":"c4f68fc3.2dd88","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":710,"y":780,"wires":[]},{"id":"6822e7f9.3973c8","type":"debug","z":"c4f68fc3.2dd88","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":710,"y":820,"wires":[]}]