Current Transmitter / Voltage Transmitter; Alarm Current / Alarm Voltage - Siemens SITRANS TW 7NG3242 Betriebsanleitung

4.2.10 Current transmitter / voltage transmitter

The transmitter can be switched to constant current or constant voltage operation for
test purposes. In this case the output current or output voltage no longer correspond
to the process variable.

4.2.11 Alarm current / alarm voltage

With this function the value of the lower and upper alarm current or the lower and
upper alarm voltage can be set. Both signal a sensor error or a hardware / firmware
error.
The value of the upper and lower alarm current / alarm voltage and the upper and
lower limit of the linear modulation range are freely selectable within the given limits
of the current modulation range / voltage modulation range. Figure 11, page 103
shows this by an example of the 4 ... 20mA current output.
The specified accuracy of the output signal only applies for the respective rated
ranges.
1. linear modulation range
2. lower limit of the modulation range (default value)
3. upper limit of the modulation range (default value)
4. lower alarm current value (default value)
5. upper alarm current value (default value)
6. recommended setting range for lower alarm current range and lower modulationrange limit
7. recommended setting range for upper alarm current range and upper modulationrange limit
Figure 11 Current limits in output signal 4 ... 20mA
SITRANS TW
A5E00054075-05
Functions / Operation by HART
Measuring range
103