Siemens SITRANS VP300, Руководство по эксплуатации, Страница: 87 / 190

Operate
6.2 Parameter description
SITRANS VP300 with or without HART
Operating Instructions, 03/2011, A5E01258666-03
85
"2.4.1.6 Current 0%" and "2.4.1.7 Current 100%"
Requirements: The setpoint direction must be observed.
"2.4.1.1 Direction" (Page 83)
Factory setting:
 Current 0%: 4.0 mA

Current 100%: 20 mA
Setting range: 4.0 ... 20.0 mA
Purpose:

Current 0%: Start of the split range
 Current 100%: End of the split range
Description: Use the "Current 0%" and "Current 100%" parameters to limit the
range of the effective setpoint. Split-range tasks, such as heating and
cooling applications or solutions for partial-load and full-load
operation, can be accomplished in this way. The master controller of
the higher-level system sends the setpoint through two positioners
connected in series electrically. The same setpoint current flows
through the two positioners. Each positioner operates in the specified
range, depending on the settings in the "Current 0%" and "Current
100%" parameters.
Note: Current 100% must be set at a value that is at least 4 mA
greater than the value of Current 0%.
By setting the setpoint direction in the "Direction" parameter
accordingly, you enable the following characteristic curves:

Rising/falling
 Falling/rising

Falling/falling
 Rising/rising