Touchpoint 4 Serial Communication Protocol Issue 1 09/07
Unit fault status:
1 byte
0x00: no fault
0x01: line circuit fault
0x02: negative draft
0x03: in DC2 AC fault
0x04: in DC2 DC low voltage
0x05: in DC2 DC fault
Channel(s) status:
6 * n bytes
(n = quantity of channels)
Every channel status has 6 bytes, defined as following:
Channel number:
1 byte (1 to 4)
Concentration format: 1 byte
Concentration:
2 bytes
Channel alarm status: 1 byte (refer to unit alarm status)
Channel fault status:
1 byte (refer to unit fault status)
Checksum:
1 byte
Each channel status data contains 6 bytes, so the length field of the response packet
depends on the quantity of the channel of Touchpoint4. For example, if there are 4
channels, the length will be
1 (C 6 (Data + Time + Unit alarm Unit fault status) + 6 (bytes per
channel) * 4 (channels) = 31.
If there are 2 channels, the length will be
1 + 6 + 6*2 =19.
Note that once instrument receives the
Get unit and points status command
, it always
send out all its channels’ status.
Example:
Example 1:
0x7f 0x01 0x0d 0x30
0x1f 0x56
date: OCT. 22, 1995
0x13 0xc0
time: 02:30:00
0x01
alarm: A1 alarm
0x00
fault: no fault
0x01
channel number: 1
0x81 0x00 0x62
concentration: 9.8 %V/V
0x01
alarm: A1 alarm
0x00
fault: no fault
0x3b
checksum
The example means this Touchpoint4 gas detector controller only has one
channel connected.
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