Operating Hours Counter - Siemens SITRANS TW 7NG3242 Betriebsanleitung

message relay
active
passive
upper
limit value
lower
limit value
Figure 15 Examples for limit value monitoring (hysteresis = 0)

4.2.16.2 Operating hours counter

An electronic operating hours counter can be read out via HART (PDM or Commu-
nicator). The counter is activated the first time the transmitter is started. If the device
is disconnected from its power supply the counter reading is stored automatically in
the non-volatile memory. It can therefore access the latest counter reading the next
time it is restarted. The operating hours counter cannot be reset.
4.2.16.3 Slave pointer
This device offers four pairs of slave pointers altogether with which the following
measuring variables and positive peak values can be monitored:
• Slave pointer pair for primary measured value (e.g. temperature difference T1-
T2 in two resistance thermometers in difference circuit)
• Slave pointer pair for secondary measured value (e.g. temperature of measuring
channel 1 in two resistance thermometers in difference circuit)
• Slave pointer pair for tertiary measured value (e.g. temperature of measuring
channel 2 for two resistance thermometers in difference circuit)
• Slave pointer pair for electronics temperature
SITRANS TW
A5E00054075-05
temperature curve
Example 1
Functions / Operation by HART
Example 2 Example 3
111