Siemens LMV5 Quick Start Manual page 210

Notes on operating modes
Modbus downtime
When deactivating the «Gateway DDC» mode (menu item «OptgModeSelect»  «GatewayDDCoff»),
Note:
automatic changeover to Local takes place, that is, preselected output «W1» will apply.
Changeover of operating mode via parameter 43
Default parameter settings
Parameter
Setpoint W1
Setpoint W2
External setpoint W3
Set target load mod / multistage
Local / Remote
Selection of manual or automatic opera-
tion
Operating mode: Remote "off" / remote
"on" / W3
Operating mode with load controller
An AZL5 reset will be triggered when switching power on, or in the event of severe system errors.
Note:
LMV5 QSG Rev 4
When there is no more communication between DDC and AZL..., the Modbus downtime is
used to switch over from Remote mode to the preselected setpoint in Local mode. The
timer will be activated when changing from Local to Remote. With every permissible Mod-
bus communication to this slave (AZL...), the timer will be reloaded.
Should the timer lapse, the DDC must again set the Remote mode, if required. The timer
value will be retained in EEPROM and will also be retained after power off.
This changeover was introduced primarily because of the requirements of boiler sequence
control.
In that case, the individual boiler can be operated at low output via manually «On». When
switching to «Auto» via sequence control, preselected output «W3» will be used.
Address Storage location
47 EEPROM
48 EEPROM
44 RAM
45 RAM
41 RAM
40 EEPROM
43 RAM
39 EEPROM
Sec 8 Pg 16
Preselection
See Basic Documentation
«Menu and parameter lists»
See Basic Documentation
«Menu and parameter lists»
«0» will be reinitialized when
resetting the AZL...
«0» will be reinitialized when
resetting the AZL...
«Local»
See Basic Documentation
«Menu and parameter lists»
«Auto» will be reinitialized when
resetting the AZL...
See Basic Documentation
«Menu and parameter lists»
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Choices for making
changes
 On the AZL...
(menu)
 Preselection via
Modbus
 On the AZL...
(menu)
 Preselection via
Modbus
 On the AZL...
(menu)
 Preselection via
Modbus
 On the AZL...
(menu)
 Preselection via
Modbus
 Via Modbus
 On the AZL...
(menu)
 Via lapse of timer
«Communication
failure» from Re-
mote to Local
 On the AZL...
(menu)
 Preselection via
Modbus