is not correct.
correct mode.
There is no
communication
between the
upper end device
and the meter
The communication baud
rate of the meter is not
correct.
Check if the communication baud rate
of the meter is consistent with its
definition.
The communication link
has not been connected
to the terminal resistor.
Check if the 120-Ohm resistor has
been connected.
The communication link
suffers interference.
Check if the communication-shielding
layer has been earthed effectively.
The communication line
is interrupted.
Check if the communication cable has
been disconnected.
The communication baud
rate of the meter is not
correct.
Check if the communication baud rate
of the meter is consistent with its
definition.
68
