I'm interested in talking with you more about this project. I will message you.

Cheers,

Although I would recommend setting packetization and character timeouts as above, this was not the underlying problem.

zzzz....zzzz....zzzz WAKE UP!!! Can't respond to MODBUS polls when it is asleep!

I thought the router or coordinator the bee was attached to would buffer the request and then send it on when it wakes,
but I could not get it to do this. even with short sleep/wake cycles under the poll timeout value.

So I made sure all my nodes are running ROUTER firmware, so the do not go to sleep.
You could run end device firmware and set the sleep mode to "Pin Sleep" and then wire
the sleep pin permanently LOW, but using ROUTER firmware allows the radio to participate in the MESH.

Also, I have the character timeout in the gateway set at 5 now, but this seems to be a grey area according to my
research. And then there is the Xbee radio paketization timeout, which I have set at 5 also, in the co-ordinator
and the end node radios, another grey area. Have not used a router in between at this stage, but may slow things
down a bit with more hops. The Arduino is sending data via its end node at only 9600! I think by adjusting the arduino
MODBUS slave library to accommodate a higher baud rate would really help.

Definitions:

Packetization Timeout
The number of character times of inter-character delay required before transmission. If set to zero, characters are
transmitted as soon as they arrive instead of buffering them into one RF packet.

Character Timeout
Specifies how long to wait for additional message data before discarding a partially received message.

I am still learning a lot about Xbee, but it appears now to transport MODBUS very successfully, especially
seeing as it it getting translated from TCP to RTU and vica versa in the gateway. My test node is pulling
4 analog values and sending one digital output every 5 seconds, but is capable of 6AI, 2AO, 6DI and 4DO.
This is all the pins used up on a Arduino UNO. You could also change the combinations if you like.

I would be happy to pass on any knowledge I have about this subject.

Below is the Mango Data source for the Arduino/Xbee node:

 {
         "xid":"DS_101326",
         "type":"MODBUS_IP",
         "alarmLevels":{
            "DATA_SOURCE_EXCEPTION":"INFORMATION",
            "POINT_READ_EXCEPTION":"INFORMATION",
            "POINT_WRITE_EXCEPTION":"INFORMATION"
         },
         "purgeType":"YEARS",
         "updatePeriodType":"SECONDS",
         "transportType":"TCP_KEEP_ALIVE",
         "encapsulated":false,
         "host":"10.1.1.12",
         "port":502,
         "contiguousBatches":false,
         "createSlaveMonitorPoints":false,
         "discardDataDelay":2500,
         "logIO":false,
         "maxReadBitCount":2000,
         "maxReadRegisterCount":125,
         "maxWriteRegisterCount":120,
         "multipleWritesOnly":false,
         "quantize":false,
         "retries":2,
         "timeout":5000,
         "updatePeriods":5,
         "enabled":true,
         "name":"Arduino1",
         "purgeOverride":true,
         "purgePeriod":1
      },

Cabinet Temperature data point:

{
         "loggingType":"INTERVAL",
         "intervalLoggingPeriodType":"MINUTES",
         "intervalLoggingType":"AVERAGE",
         "purgeType":"YEARS",
         "pointLocator":{
            "range":"INPUT_REGISTER",
            "modbusDataType":"TWO_BYTE_INT_UNSIGNED",
            "writeType":"NOT_SETTABLE",
            "additive":0.0,
            "bit":0,
            "charset":"ASCII",
            "multiplier":0.488,
            "offset":3,
            "registerCount":0,
            "slaveId":1,
            "slaveMonitor":false
         },
         "eventDetectors":[
            {
               "xid":"PED_959001",
               "type":"HIGH_LIMIT",
               "alarmLevel":"CRITICAL",
               "limit":45.0,
               "durationType":"MINUTES",
               "duration":1,
               "alias":""
            }
         ],
         "engineeringUnits":"Degrees celsius",
         "plotType":"STEP",
         "chartColour":"",
         "chartRenderer":{
            "type":"IMAGE",
            "timePeriodType":"HOURS",
            "numberOfPeriods":8
         },
         "dataSourceXid":"DS_101326",
         "defaultCacheSize":1,
         "deviceName":"Arduino1",
         "discardExtremeValues":false,
         "discardHighLimit":45.0,
         "discardLowLimit":5.0,
         "enabled":true,
         "intervalLoggingPeriod":15,
         "name":"Cabinet Temperature",
         "purgeOverride":true,
         "purgePeriod":1,
         "textRenderer":{
            "type":"ANALOG",
            "format":"0.00",
            "suffix":"°C in Pole Cabinet"
         },
         "tolerance":0.25,
         "xid":"DP_144357"
      },

I have outputs staying on now, after trying just about every setting in Mango and the gateway.
The system is operating without errors now, which I think is pretty good considering the low tech
Arduino hardware and basic Modbus RTU slave code.

I can give you access (assuming you are from Infinite Automation), but I am running the free Mango version, and is working on only one client IP
address.

I also use Advantech ADAM-6000 Modbus TCP modules with Mango and they are working flawlessly.

Mango is such a great package. I am starting a Environmental monitoring/automation business and after the testing I have done
so far with Mango, this is what I will be running with.

Hayden

Re the problem you have, is there a way that you can make something accessible via the internet so that i can experiment? PM me with deets if so. Perhaps what is needed is some kind of continual reminder to the point to stay on. Without a test bed i'd just be guessing as to what the problem could be.