WIKA CTH6300 - Handbuch (Seite 33)

33 WIKA operating instructions, models CTH6300 and CTH6500
2079988.04 07/2014 GB/D
GB
6. Commissioning, operation / 7. Interface protocol RS-232
6.8 Special functions
6.8.1 Ohm/Microvolt/Volt/Hertz display
To display the indicated values in the corresponding basic unit, during switching on
simultaneously press FAST/▼ and ON/OFF button and keep them pressed for approx.
3 seconds until the following basic unit is displayed:
o = Ohm (Pt100)
H = Hertz (flow m/s)
u
Microvolt (thermocouples)
U Volt (humidity)
6.8.2 Zero point adjustment (zero)
Keep the Clear key pressed (for approx. 3 seconds) to set the displayed value to 0.
Before pressing the key make sure that the actual value is also 0 (no flows/pressure
available at the probe).
6.8.3 Deactivation of channel 2 (Toggle)
Keep the Hold key pressed (for approx. 3 seconds) to deactivate or activate the 2nd
measuring channel.
7. Interface protocol RS-232
During data transfer make sure that the voltage levels for the signals RTS = +12 V and
DTR = -12 V are provided by the PC. This must be implemented by means of software
interface initialisation.
Parameters
Baud rate 2,400 baud
Data bits 8
Stop bits 2
Parity None
To transfer the measured values, the following requests must be sent to the measuring
instrument. The following table illustrates which values can be requested via the
interface.