Installation 29
Invalid Request
If the WattNode Modbus meter receives a
valid packet
, but with an
invalid
request
(see below), then the meter will respond with a Modbus exception mes-
sage and store an error in the
registers. Because the packet was valid,
Com
LED will
flash green for 200 milliseconds.
Modbus Exceptions
If the meter receives an invalid request, it will reply with a Modbus exception code. In most cases,
your PC software should be able to display the code, which should help you determine the prob-
lem. For more information about the problem, check the
registers, which will provide
more detailed error codes.
●
01 - Illegal function code
○
ErrorStatus 213: The Modbus function code is not supported by the WattNode meter,
such as
07 Read Exception Status
.
●
02 - Illegal data address
○
ErrorStatus 206: Attempted to read an invalid register address or write to a read-only
register. This is common if your addresses are off by one or you request extra registers.
○
ErrorStatus 203: A partial 32 bit write (a dual register like
ConfigPasscode
) was aborted
by a write to an unrelated register.
●
03 - Illegal data value
○
ErrorStatus 202: When changing the
ConfigPasscode
, the confirmation entry didn’t
match the first entry.
○
ErrorStatus 205: Invalid
ConfigPasscode
value entered. You will have to wait five
seconds to try again.
○
ErrorStatus 207, 208: An attempt was made to write an illegal data value to a register.
○
ErrorStatus 211, 212: The Modbus packet contained an invalid count of registers or an
invalid byte count.
●
04 - Slave device failure
○
ErrorStatus 200: The correct
ConfigPasscode
must be entered before changing con-
figuration registers, or resetting the energy or demand registers.
○
ErrorStatus 19, 20, 72, 79, 80, 215: Internal hardware failure.
○
ErrorStatus 67: Calibration data lost. The WattNode meter will report a slave device
failure until it is calibrated.
●
06 - Slave device busy
○
ErrorStatus 209: Attempts to unlock the configuration with
ConfigPasscode
are locked
out for five seconds after entering an invalid passcode.
Review Diagnostic Registers
If Modbus communications are working, but with intermittent problems, check the following diag-
nostic registers (see
for details):
,
0.2s
Green Off
