INFICON Composer Elite Gas Concentration Monitor - Manual (Page 89)

5 - 23
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07
4-
56
6-
P1
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Composer Elite Operating Manual
5.5.2.1 Response Packet (Composer Elite to Host Message)
Parameter>
Length . . . . . . . . . . . . . . . . . . . . . . . 2 bytes Low / High (not including checksum
or length bytes). Numeric value representing
the number of characters in the response.
Two byte values, high and low order, are
required to represent this number. In order of
transmission, the low byte will precede the
high byte.
Command . . . . . . . . . . . . . . . . . . . . Reports the command sent by the host.
Command ID . . . . . . . . . . . . . . . . . . Reports the subcommand sent by the host.
Sensor . . . . . . . . . . . . . . . . . . . . . . . Reports the sensor number sent by the host.
Internal Parameter . . . . . . . . . . . . . Reports the parameter number sent
by the host.
Status. . . . . . . . . . . . . . . . . . . . . . . . Received as a hex value. Converted to Bits:
. See Table 5-18 .
Message . . . . . . . . . . . . . . . . . . . . . This field contains the data being sent to the
requesting application by Composer Elite.
This field is optional and the format of any
returned data is determined by the specific
command. Refer to
section 5.6 for a detailed
description of all possible responses.
Checksum . . . . . . . . . . . . . . . . . . . . 1 byte, sum, modulo 256, of all bytes, not
including length and checksum. Modulo 256
is the numeric value from 0 to 255
representing the modulo 256 remainder of
the sum of the values of the ASCII codes that
comprise the response.
5.5.2.2 Communication Error Codes
If there was an error detected with the command sent to Composer Elite, the
response message will have the MSB of the status byte (SS bit) cleared (see
Table
5-18 on page 5-24 ). The data portion of the message will be one byte long and will
be one of the following:
3 (0x03) . . . . Message length is zero*
10 (0x0A) . . . Invalid sensor number
11 (0x0B) . . . Invalid program number