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As a policy of continual improvement, RMF reserves the right to alter the specification without prior notice.
201.028 REV 1
Date of Issue: 18 June 2018
6.4.1.2 Result Codes
The most recent measurements are presented as numeric codes (i.e. numbers) according to the selected TEST
FORMAT. These codes can be read from registers 56-63, as per Table 6B.
Register
ISO 4406 Code AS4059E Table 2
Class
NAS1638/ AS4059E Table 1/ ISO
11218 (Draft) Codes/ Classes
56
≥4µ
Basic
Basic
57
≥6µ
-
-
58
≥14µ
A
5-15
59
≥21µ
B
15-25
60
≥25µ
C
25-50
61
≥38µ
D
50-100
62
≥50µ
E
100+
63
≥70µ
F
Table 6B RESULT CODES Registers 56-63
6.4.1.2.1 Null Values
For all formats, the special value -
32768 (0x8000 hex) is used to represent a ``null’’ or ``no result’’ condition. This
enables ``No Result’’ to be distinguished from a 0/0/0 ISO code, for example. ``No Result’’ could be due to an
error condition, or to a measurement not having been commanded yet. This convention is also used for other
parameters such as temperature and water content measurements, where applicable.
NOTE: User written programs should take note, to avoid displays like -32768/-32768/-32768 appearing on their
front panels.
6.4.1.2.2 ISO4406
ISO 4406 defines a set of code values to represent ranges of counts of particles greater than the nominated sizes
of ≥4,
≥6 and ≥14μm(c). The
CMS can display codes from 0 to 24. The three-part code is available in the first 3
RESULT CODES.
We additionally make available equivalent codes for the other sizes from 21 to 70μm(c), as per Table 6B.
6.4.1.2.3 NAS 1638/ AS4059E-1/ ISO11218
These assign code numbers f
or the particle counts in each size range shown in the table. The ``basic’’ class is then
the highest of these individual codes. The basic class is in the first register, with the individual classes made
available in the registers shown.
For these standar
ds there is a complication in that they all define an additional class ``00’’. This is an extra
``cleaner than class 0’’ class. We distinguish this from 0 using the numeric value
-1. Negative numbers are
represented in a Modbus register using the ``twos co
mplement’’ notation. If the user program interprets this as a
positive number it will appear as 65535 (0xFFFF hex).
Classes range from 00(-1) to 12.
Summary of Contents for CMS 2
Page 1: ...User Manual CMS2...
