Timeout In The Event Of Communication Breakdown; Preselected Output In The Event Of Communication Breakdown; Activation Of Modbus - Siemens LMV3 series Technical Instructions

Technical Instructions
Document No. LV3-1000

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
142 120 sec

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
148/149 Not set

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
141 0
Section 7
Range
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
0-7200 sec will wait for the Modbus communication to be available
again.
0 = none
1 = odd
2 = even
Range
This sets the fire rate when Modbus communication is
interrupted. A setting from 20-100% will set the output
0-100%
of the burner. A setting of 0-19.9% will shut down the
burner.
Range
Sets the Modbus operating mode:
0 = off (inactive)
0-2
1 = on (active)
2 = not used
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Description
Description
Description
LMV Series
SCC Inc.