You would use a catch node to catch the error message, select the ftp node in the catch node config. A simple switch node with rule == to direct the success, you can also use otherwise in the switch node rules to direct any other response.
Example
[{"id":"5594c86bcd8f5e6d","type":"inject","z":"d1395164b4eec73e","name":"put","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"PUT Operation successful","payloadType":"str","x":170,"y":3100,"wires":[["90f398c848510ac6"]]},{"id":"90f398c848510ac6","type":"switch","z":"d1395164b4eec73e","name":"","property":"payload","propertyType":"msg","rules":[{"t":"eq","v":"PUT operation successful","vt":"str"},{"t":"else"}],"checkall":"true","repair":false,"outputs":2,"x":330,"y":3100,"wires":[["ad128ba84e8ec9ae"],["8f5a15c392e69325"]]},{"id":"e9d94eff8ad3dc28","type":"inject","z":"d1395164b4eec73e","name":"error","props":[{"p":"error","v":"Timeout","vt":"str"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","x":170,"y":3160,"wires":[["90f398c848510ac6"]]},{"id":"ad128ba84e8ec9ae","type":"debug","z":"d1395164b4eec73e","name":"success","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":460,"y":3080,"wires":[]},{"id":"8f5a15c392e69325","type":"debug","z":"d1395164b4eec73e","name":"error","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":450,"y":3120,"wires":[]}]