MP Filtri ICM, User Manual

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62 Analog 4-20mA Modes
20.2.4 ISO4406
Parameters are output in the sequence
<SYNC> <ISO4> <ISO6> <ISO14> <ISO21> <ISO25> <ISO38> <ISO50> <ISO70>
<RH> <TEMP> <...>
ISO4406 codes are encoded as
𝑚𝐴 = 6 + 𝐼𝑆𝑂/2
(20.6)
or
𝐼𝑆𝑂 = 2 × (𝑚𝐴 − 6)
(20.7)
So 6mA = ISO 0, 20mA = ISO28
20.2.5 AS4059E2
Parameters are output in the sequence:
<SYNC> <BASIC> <A> <B> <C> <D> <E> <F> <RH> <TEMP> <...>
AS4059E2 contamination codes are encoded as
𝑚𝐴 = 6 + ((𝑐𝑜𝑑𝑒 + 2)/2)
(20.8)
or
𝑐𝑜𝑑𝑒 = 2 × (𝑚𝐴 − 6) − 2 = 2 × 𝑚𝐴 − 14
(20.9)
so that 6mA = -2 = 000, 6.5mA = -1 = 00, 7.0mA = 0, 7.5mA = 1, 13mA = 12 =
max valid reading, 20 mA = overrange
20.3 Time Multiplexed - Scheme 2
This outputs the parameters as currents, using values designed for viewing directly
on a programmable process meter. There is no "sync" value but the final parameter
stays on for 2 seconds instead of 1. To avoid confusion the RH channel does not
output temperature (just static RH value). The other channel outputs just the overall
contamination code value except for ISO4406 where it cycles between 3 ISO codes.