Datasheet

4
sensing.honeywell.com
Particulate Matter Sensors
HPM Series
Table 4. Standard Version Customer Use Protocol
1
Command Length
(Bytes)
HEAD LEN CMD Data CS Example
Read Particle Measuring Results
Send 0x68 0x01 0x04 NA
CS = MOD
((65536-(HEAD+LEN+CMD+DATA)), 256)
68 01 04 93
Response, Pos ACK 0x40 0x05 0X04
“DF1, DF2, DF3, DF4
PM2.5 = DF1 * 256 + DF2
PM10 = DF3 * 256 + DF4”
CS = MOD
((65536(HEAD+LEN+CMD+DATA)),
256)
40 05 04 00
30 00 31 56
Response, Neg ACK 0X9696
Start Particle Measurement
Send 0x68 0x01 0x01 NA
CS = MOD
((65536-(HEAD+LEN+CMD+DATA)), 256)
68 01 01 96
Response, Pos ACK 0xA5A5
Response, Neg ACK 0x9696
Stop Particle Measurement
2
Send 0x68 0x01 0x02 NA
CS = MOD
((65536-(HEAD+LEN+CMD+DATA)), 256)
68 01 02 95
Response, Pos ACK 0xA5A5
Response, Neg ACK 0x9696
Set Customer Adjustment Coefficient
Send 0x68 0x02 0x08
DF1: 30 ~ 200
(Default, 100)
CS = MOD
((65536-(HEAD+LEN+CMD+DATA)), 256)
68 02 08 64 2A
Response, Pos ACK 0xA5A5
Response, Neg ACK 0x9696
Read Customer Adjustment Coefficient
Send 0x68 0x01 0x10 NA
CS = MOD
((65536-(HEAD+LEN+CMD+DATA)), 256)
68 01 10 87
Response, Pos ACK 0X40 0X02 0X10
DF1: 30 ~ 200
(Default, 100)
CS = MOD
((65536-(HEAD+LEN+CMD+DATA)), 256)
40 02 10 64 4A
Response, Neg ACK 0x9696
Stop Auto Send
Send 0x68 0x01 0x20 NA
CS = MOD
((65536-(HEAD+LEN+CMD+DATA)), 256)
68 01 20 77
Response, Pos ACK 0xA5A5
Response, Neg ACK 0x9696
Enable Auto Send
3
Send 0x68 0x01 0x40 NA
CS = MOD
((65536-(HEAD+LEN+CMD+DATA)), 256)
68 01 40 57
Response, Pos ACK 0xA5A5
Response, Neg ACK 0x9696
1
Product life may vary depending on the specific application in which the sensor is utilized.
2
Shuts down the fan, helping to extend the life of the product.
3
See Table 6 for data format.