YOKOGAWA vigilantplant EXA ISC202G, User Manual

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IM 12D06A03-01E
5-16 Parameter setting
Fig. 5-1. Linearization of output
Example: 0-25% Sulfuric acid
5-3-4. mA output functions
Code 31 *OUTP.F For the ISC202 the output may be chosen as linear to input, or configured in
a 21 point table to a particular linearization. Enable the table setup in code 31,
and configure the table in code 35.
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
signaling 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 linearize the output with a mA curve.
mA
1,000
800
600
400
200
0
CONDUCTIVITY (S/cm)
CONCENTRATION (%)
100 80 60 40 20 0
Output in %
100 80 60 40 20 0
0
5
10
15
20
25
Output in %
Code
Output 4-20 mA % H2SO4
Service
code 55 mS/cm
Service
code 35 Default
mS/cm
0 4.0 0.00 0 0
5 4.8 1.25 60 50
10 5.6 2.50 113 100
15 6.4 3.75 180 150
20 7.2 5.00 218 200
25 8.0 6.25 290 250
30 8.8 7.50 335 300
35 9.6 8.75 383 350
40 10.4 10.00 424 400
45 11.2 11.25 466 450
50 12.0 12.50 515 500
55 12.8 13.75 555 550
60 13.6 15.00 590 600
65 14.4 16.25 625 650
70 15.2 17.50 655 700
75 16.0 18.75 685 750
80 16.8 20.00 718 800
85 17.6 21.25 735 850
90 18.4 22.50 755 900
95 19.2 23.75 775 950
100 20.0 25.00 791 1000
Table 5-3.