HLS-442 datasheet(8/22 Pages) AMSCO

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[v1-00] 2015-Mar-30

HLS-442 − Electrical Inter face

H2 Concentration

0% is encoded with decimal number 20.

4.4% (44000 ppm) is encoded with decimal number 240.

The relation between detected H2 concentration (in ppm) and

concentration code as signaled in the message is:

Code = round(H2/200) + 20

H2 = (code – 20)*200

Where round() denotes rounding towards the nearest integer.

Protection Value

The protection value offers a 10-bit consistency check of the

transmitted concentration, status and message counter. The

following pseudo code describes the algorithm forming the

10-bit value and how it is projected on to the protection value

1 and the protection value 2 bytes in the SSM.

code[7 - 0] denotes the set of 8 bits transmitted as code for

representing the H2 concentration.

status[1 - 0] denotes the set of two bits transmitted as code for

representing sensor status.

mgscnt[6 - 0] denotes the set of 7 bits transmitted as code for

representing message counter.

pv[9 - 0] denotes the set of 10 bits forming the protection value.

pv1[7 - 0] denotes the set of 8 bits transmitted as code for

protection value 1.

pv2[1 - 0] denotes the set of 2 bits transmitted as code for

protection value 2.

(EQ1)

(EQ2)

HLS-442 Datasheet(PDF) 8 Page - ams AG