Appendix
3
Cole Palmer
The master sets parameters in the chiller by sending one of the Set Functions as shown in Table 1. The master
does not send a qualier byte in the data eld. The master should be preprogrammed to send the correct precision
and units (it could also read the parameter of interest rst to decode the correct precision and units needed).
As an example, if the master wants to set the setpoint to 30°C, it would send :
Table 1 Commands (All bytes are in hex)
FUNCTION MASTER SENDS UNIT RESPONDS
Read Acknowledge CA 00 01 00 00 FE CA 00 01 00 02(v1)(v2)(cs)
Read Status (see Table 3) CA 00 01 09 00 F5 CA 00 01 09 02(d1)(d2)(cs)
Error CA 00 01 0F 02(en)(ed)(cs)
Read Internal Temperature (RTD1) CA 00 01 20 00 DE CA 00 01 20 03(qb)(d1)(d2)(cs)
Read External Temperature (RTD2) CA 00 01 21 00 DD CA 00 01 21 03(qb)(d1)(d2)(cs)
Read Setpoint One CA 00 01 70 00 8E CA 00 01 70 03(qb)(d1)(d2)(cs)
Read Low Temperature Warning CA 00 01 40 00 BE CA 00 01 40 03(qb)(d1)(d2)(cs)
Read Low Temperature Fault CA 00 01 41 00 BE CA 00 01 41 03(qb)(d1)(d2)(cs)
Read High Temperature Warning CA 00 01 60 00 9E CA 00 01 60 03(qb)(d1)(d2)(cs)
Read High Temperature Fault CA 00 01 61 00 BE CA 00 01 61 03(qb)(d1)(d2)(cs)
Read Cool Proportional Band (P) CA 00 01 74 00 8A CA 00 01 74 03(qb)(d1)(d2)(cs)
Read Cool Integral (I) CA 00 01 75 00 89 CA 00 01 75 03(qb)(d1)(d2)(cs)
Read Cool Derivative (D) CA 00 01 76 00 88 CA 00 01 76 03(qb)(d1)(d2)(cs)
Read Heat Proportional Band (P) CA 00 01 71 00 8D CA 00 01 71 03(qb)(d1)(d2)(cs)
Read Heat Integral (I) CA 00 01 72 00 8C CA 00 01 72 03(qb)(d1)(d2)(cs)
Read Heat Derivative (D) CA 00 01 73 00 8B CA 00 01 73 03(qb)(d1)(d2)(cs)
command bytes shown in bold v1, v2 = protocol version
qb = qualifier byte, see Table 2 ed Bad command byte gets echoed)
d1,d2 = 16 bit signed integer of the value being en (error number) 01 = Bad command,
sent or received 02 = Bad checksum
cs = the checksum of the string (see text) xx = no valid data, include in checksum
CA 00 01 F0 03 11 01 2C CD
command byte
3 bytes to follow
The checksum is the bitwise inversion of 22
(00+01+F0+03+01+2C)
Take the LSB=32
The qualifier byte of 11 indicates a precision of 1
decimal point and units of °C. The temperature of
30°C is 300 decimal = 012C hex.
command byte
2 bytes to follow
The checksum is the bitwise inversion of 20
(00+01+F0+02+01+2C)
Take the LSB=22
The temperature of 30.0°C is 300 decimal = 012C hex.
CA 00 01 F0 02 01 2C DF
Unit responds:
unit address
(defaults to 01)
unit address
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