
EM-RS485 Modbus Protocol Guide
Page 9 of 52
154-0023-0B
R112 Auto Protocol
BOOL R/W/NV
Sets the state of automatic protocol detection:
0.
Inactive
1.
Active
When
Active
, the RS485 receiver initially allows frames of any supported protocol. On establishing
confidence in a particular protocol (about 10 consecutive frames of the same type), this becomes
the preferred
RS485 Protocol
(see
).
Generally, having a preferred protocol disallows other protocols. This reduces uncertainty in the
unlikely event that a particular frame or sequence could be interpreted as more than one protocol.
However, should the protocol really change (e.g. by moving the meter to a different network), the
meter will eventually lose confidence in the preferred protocol. After temporarily allowing all
protocols, automatic protocol detection will establish a new preference. To avoid the delays
associated with changing protocol, set the
RS485 Protocol
to some option that permanently allows
multiple protocols.
When changing this value, the meter keeps the current
RS485 Protocol
to avoid communication
loss. Setting
Inactive
disables further automatic protocol changes and only allows the protocol(s)
specifically set in
RS485 Protocol
.
Default:
Active
R114 Auto Baud Rate
BOOL R/W/NV
Sets the state of automatic baud rate detection:
0.
Inactive
1.
Active
When
Active
, the meter may automatically change the
Baud Rate
(see
) in response to RS485
communication errors. When changing this value, the meter always keeps the current
Baud Rate
to
avoid communication loss.
Default:
Active
R116 Auto Parity
BOOL R/W/NV
Sets the state of automatic parity detection:
0.
Inactive
1.
Active
When
Active
, the meter may automatically change the
Parity
(see
) in response to RS485
communication errors. When changing this value, the meter always keeps the current
Parity
to
avoid communication loss.
Default:
Active
R117 Auto Data Bits
BOOL R/W/NV
Sets the state of automatic data bits detection:
0.
Inactive
1.
Active
When
Active
, the meter may automatically change the
Data Bits
(see
) in response to RS485
communication errors. When changing this value, the meter always keeps the current
Data Bits
to
avoid communication loss.
Default:
Active