Subflow with environment variabel

[{"id":"46d7d977.fd5fa8","type":"subflow","name":"Sub watch flow variable","info":"","category":"","in":[],"out":[{"x":800,"y":100,"wires":[{"id":"ebd9e58e.15c048","port":0}]}],"env":[{"name":"FlowMemName","type":"str","value":"\"\"","ui":{"type":"input","opts":{"types":["str"]}}},{"name":"PollIntevall_ms","type":"num","value":"1000","ui":{"type":"input","opts":{"types":["num"]}}}],"meta":{},"color":"#DDAA99"},{"id":"8e9568e8.406838","type":"inject","z":"46d7d977.fd5fa8","name":"Initiate","props":[{"p":"payload"}],"repeat":"","crontab":"","once":true,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":110,"y":100,"wires":[["b015103c.dd7ee"]]},{"id":"ebd9e58e.15c048","type":"function","z":"46d7d977.fd5fa8","name":"check change","func":"let varName = env.get(\"FlowMemName\"); \nlet status = flow.get(\"$parent.\" + varName) || false;\n\nif (typeof status === 'object'){\n    status = JSON.stringify(status);\n}\n\nlet isEqual = (status === context.statusMem);\ncontext.statusMem = status;  \n\nif(isEqual || (status === null))\n    return null;\n\n\n//Ändrats\nlet newMsg = {};\nnewMsg.payload= {status, \n                    \"meta\": {\n                        \"varname\": varName,\n                        \"timestamp\":  msg.timestamp\n                    }\n                }\n\nreturn newMsg;\n\n\n","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":640,"y":100,"wires":[[]]},{"id":"b015103c.dd7ee","type":"change","z":"46d7d977.fd5fa8","name":"timestamp","rules":[{"t":"set","p":"timestamp","pt":"msg","to":"","tot":"date"}],"action":"","property":"","from":"","to":"","reg":false,"x":370,"y":100,"wires":[["ebd9e58e.15c048","495b825a.1f582c"]]},{"id":"495b825a.1f582c","type":"delay","z":"46d7d977.fd5fa8","name":"poll intervall","pauseType":"delay","timeout":"${PollIntevall_ms}","timeoutUnits":"milliseconds","rate":"1","nbRateUnits":"1","rateUnits":"second","randomFirst":"1","randomLast":"5","randomUnits":"seconds","drop":false,"outputs":1,"x":370,"y":180,"wires":[["b015103c.dd7ee"]]},{"id":"66696123.15d23","type":"comment","z":"46d7d977.fd5fa8","name":"subflow","info":"","x":370,"y":20,"wires":[]}]