IM12B07D02-01E
Parameter setting 5-17
5-3-4. mA output functions
Code 31 *OUTP.F When pH is set in code 01 as the main parameter, the output functions may be
set as follows:-
0: pH
1: pH (table)
2: Parameter 2 (ORP or rH as set in code 02)
When ORP is set in code 01 as the main parameter, the output functions may
be set to:
0: ORP
1: ORP (table)
Code 32 *BURN Diagnostic error messages can signal a problem by sending the output signals
upscale or downscale (21 mA or 3.6 mA when HART or distributor comm. is
non-used, 3.9 mA when HART or distributor comm. is used). This is called
upscale or downscale burnout, from the analogy with thermocouple failure
signalling of a burned-out or open circuit sensor. The pulse burnout setting
gives a 21 mA signal for the first 30 seconds of an alarm condition. After the
“pulse” the signal returns to normal. This allows a latching alarm unit to record
the error. In the case of the EXA the diagnostics are extensive and cover the
whole range of possible sensor faults.
Code 35 *TABLE The table function allows the configuration of an output curve by 21 steps
(intervals of 5%).
The following example shows how the table may be configured to linearise the
output with a mA curve.
Table 5-2.
4-20 mA 4-20 mA
0% 4.0 mA 50% 12.0 mA
5% 4.8 mA 55% 12.8 mA
10% 5.6 mA 60% 13.6 mA
15% 6.4 mA 65% 14.4 mA
20% 7.2 mA 70% 15.2 mA
25% 8.0 mA 75% 16.0 mA
30% 8.8 mA 80% 16.8 mA
35% 9.6 mA 85% 17.6 mA
40% 10.4 mA 90% 18.4 mA
45% 11.2 mA 95% 19.2 mA
100% 20.0 mA
mA
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