Siemens LMV3 series User Manual

Technical Instructions LMV Series
Document No. LV3-1000
Section 7 Page 16 SCC Inc.
Timeout in the event of communication breakdown
Setting the timeout for communication loss between Modbus and the LMV3 is made via parameter 142.
When this time has elapsed, the Modbus operating mode changes automatically from «remote» to
«local» and the output specified by parameter 148/149 will be delivered. The timeout is stored in
nonvolatile memory in the LMV3. Changes to parameter 142 can be made via the LMV3… and via
Modbus.
Parameter
Default
Range
Description
142 120 sec 0-7200 sec
If no communication occurs for this period of time, the
LMV3 considers the Modbus to be unavailable and will
look for a fire rate command from another source. A
setting of 0 makes the timeout inactive and the LMV3
will wait for the Modbus communication to be available
again.
0 = none
1 = odd
2 = even
Preselected output in the event of communication breakdown
Setting the fire rate when Modbus communication is interrupted is made via parameter 148 (fuel 0) and
149 (fuel 1). The output set with this parameter is approached when, in remote operation,
communication is interrupted for longer than the period of time set by parameter 142. If this output is
set «invalid» and communication is interrupted, the system will deliver the output set on the LMV3. The
fire rate is stored in nonvolatile memory in the LMV3. Changes to parameter 148/149 can be made via
the LMV3… and via Modbus.
Parameter
Default
Range
Description
148/149 Not set 0-100%
This sets the fire rate when Modbus communication is
interrupted. A setting from 20-100% will set the output
of the burner. A setting of 0-19.9% will shut down the
burner.
Activation of Modbus
Setting the Modbus operating mode is made via parameter 141. Modbus functionality on the LMV3 will
be activated when setting this parameter to 1. The operating mode is stored in nonvolatile memory in
the LMV3. Changes to parameter 141 can only be made via the LMV3…, not via Modbus.
Parameter
Default
Range
Description
141 0 0-2
Sets the Modbus operating mode:
0 = off (inactive)
1 = on (active)
2 = not used

Siemens LMV3 series Specifications

General

Brand	Siemens
Model	LMV3 series
Category	Control Unit
Language	English