Yokogawa EXA PH202 2-Wire pH/ORP Analyzer - Manual (Page 91)

IM 12B07D02-01E
Appendix 10-5
10-4. Set up for other functions
• Current
outputs
Transmission signals for the measured parameters and FAIL signals can be set up in service codes
31, 32 and 35.
• Diagnostic Checks
Impedance checks, response time and stability checks are all included in the PH202. In order to get the
best performance from each of these features, the transmitter should be fine tuned according to experi-
ence in the installation, and for the particular sensors selected. Service codes 3, 4, 5 & 20 all contribute to
the diagnostics. Please note that the default settings provide an excellent starting point and provide most
valuable information about the performance of the electrode system.
• Communications
The proprietary HART (FSK) communication link allows remote configuration and data retrieval
through the PC202 communication package. This is an excellent tool for the maintenance engineer,
quality engineer or plant manager. Service codes 60-62 are used to set up the communications.
• Logbook
In combination with the communications link, a “logbook” is available to keep an electronic record of
events such as error messages, calibrations and programmed data changes. By reference to this
log, users can easily evaluate diagnostic information to determine predictive maintenance schedules.
For example, by monitoring the deterioration in the slope of the pH sensor, it can be changed before
a failure (or process shutdown) occurs.
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