Honeywell Touchpoint 4 User Manual

Touchpoint 4 Serial Communication Protocol Issue 1 09/07
Concentration Data Format Code
   UUXXXYYY
UU Unit
    UU=00ppm
    UU=01%LEL
    UU=10%V/V
    UU=11kppm
   XXX reserved
YYY decimal place
    YYY=000 nodecimalplaces
    YYY=001 1decimalplace
    YYY=010 2decimalplaces
    YYY=011 3decimalplaces
Forexample,(HEX)81(10000001)represents%V/Vwith1decimalplace.
Concentration Example:
Foraconcentrationvalue(HEX)0062,98decimal,FormatCodeInterpretation:
  00000000(00) 98ppm
  10000001(81) 9.8%V/V
  01000000(40) 98%LEL
Generic Responses
There are four generic responses. Each of these response packets is 6 bytes, and
contains the start byte, address, length, command code, ACK/NAK code and
Checksum. All ACK/NAK code is sent following the command code in the last
received packet.
ACK - 0x01
This is used for an acknowledgement of the handshake command.
NAK - 0x21
This is used for a negative acknowledgement of packet if the last received packet had
an incorrect checksum.
Bad Packet - 0x66
This is sent to the master when the start byte or length in the last received packet
is incorrect.
Unknown CMD –0x67
This response is sent by the slave when a command is not recognized.
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Honeywell Touchpoint 4 Specifications

General

Brand	Honeywell
Model	Touchpoint 4
Category	Gas Detectors
Language	English