Conair MPA Refrigerator User Manual


 
UGH004/0999 CHILLER SPI COMMANDS
APPENDIX B-1
The SPI commands supported by Conair microKool portable
chillers are listed in the following tables.
The standard required commands and three optional com-
mands are listed in the SPI Command Pairs table, along with
the Select and Poll command pairs in hexadecimal format.
Select commands set or change chiller functions. Poll com-
mands retrieve information from the chiller.
See the tables on the following pages for the SPI status words
and BIT positions for Process Status, Machine 1 Status and
Machine 2 status.
For more information on the SPI protocol, you can obtain the
SPI Communication Protocol Manual by contacting:
The Society of the Plastics Industry, Inc.
1801 K Street, NW, Suite 600K
Washington, D.C. 20006
(202) 974-5200 Fax: (202) 296-7005
www.plasticsindustry.org
SPI COMMANDS
SUPPORTED BY
THE
CONAIR
MICRO
K
OOL
SPI Command Pairs
Portable chillers Device ID: hex 21
Commands Select Poll
Echo 0x21 0x21
- Select stores 4 bytes of information at the chiller; Poll retrieves it. 0x21 0x20
Setpoint Process Temperature 0x21 0x21
- Sets and retrieves the process temperature setpoint. 0x31 0x30
Alarm, High Temperature Deviation* 0x21 0x21
- Sets the alarm band temperature; retrieves setpoint + alarm band value.
0x33 0x32
Alarm, Low Temperature Deviation* 0x21 0x21
- Sets the alarm band temperature; retrieves setpoint + alarm band value. 0x35 0x34
Mode, Machine 0x21 0x21
- Start/stops the chiller; acknowledges alarms; retrieves run status
0x49 0x48
Version 0x21
- Retrieves 4 bytes of SPI version information. 0x22
Process Status 0x21
- Retrieves run status and alarm conditions. 0x40
Status, Machine 1 0x21
- Retrieves run status and alarm conditions.
0x42
Status, Machine 2 0x21
- Retrieves run status and alarm conditions. 0x44
Temperature, from Process 0x21
- Retrieves the actual temperature of fluid returning to the chiller. 0x72
* NOTE: Both High and Low Temperature Deviation commands set the
same variable. Use only one of these commands to avoid problems.