Two misunderstandings there, I think. Firstly, it looks as if the Arduino wasn’t sending the data in the format that emonHub expects, and secondly, that’s exactly what happens: the Arduino/emonTx/emonTH are expected to send the data, emonHub/emonCMS doesn’t ask for it. That’s fundamental to the OEM philosophy.
Here’s a slice of code from an emonTx sketch, showing the data and more importantly, the format in which it’s sent:
#ifdef EMONHUBTX3EINTERFACER
// ---------------------------------------------------------------------
// Key:Value format, used by EmonESP & emonhub EmonHubTx3eInterfacer
// ---------------------------------------------------------------------
Serial.print(F("MSG:")); Serial.print(emontx.Msg);
if (CT1) { Serial.print(F(",P1:")); Serial.print(emontx.P1); }
if (CT2) { Serial.print(F(",P2:")); Serial.print(emontx.P2); }
if (CT3) { Serial.print(F(",P3:")); Serial.print(emontx.P3); }
if (CT4) { Serial.print(F(",P4:")); Serial.print(emontx.P4); }
if (CT1) { Serial.print(F(",E1:")); Serial.print(emontx.E1); }
if (CT2) { Serial.print(F(",E2:")); Serial.print(emontx.E2); }
if (CT3) { Serial.print(F(",E3:")); Serial.print(emontx.E3); }
if (CT4) { Serial.print(F(",E4:")); Serial.print(emontx.E4); }
if (emontx.T1!=30000) { Serial.print(F(",T1:")); Serial.print(emontx.T1*0.01); }
if (emontx.T2!=30000) { Serial.print(F(",T2:")); Serial.print(emontx.T2*0.01); }
if (emontx.T3!=30000) { Serial.print(F(",T3:")); Serial.print(emontx.T3*0.01); }
Serial.print(F(",pulse:")); Serial.println(emontx.pulse);
#else
... ['standard' format]
So you need to copy that format for whatever data you want to send.
You did follow up with the change to emonHub for the serial interfacer?
I think emonCMS choked on that.
The old emonLib sketches used to pause for 10 s between sampling the power, so a snapshot was sent every 10 s, which emonCMS can easily keep up with. The modern emonLibCM (Zip download here: EmonLibCM - Version 2.2.2) samples continuously and sends the average for that period - we keep to 10 s (actually a bit less at 9.85 s because of the way emonCMS works - but in principle you can set any sensible period, the limits are in the documentation that comes with the library (along with example sketches).