Kodiak
Recirculating Chiller Technical Manual
Manual# 820-0043 Rev N, 11/25/2019
42
Boyd KodiakTM Chiller Control
Host Interface Data Link
1. Host Interface Data Link
The chiller supports basic host control capability through the Chiller RS-232 port.
1.1 Port Settings
The host port runs at 9600 baud, 8 data bits, 1 stop bit, no parity.
1.2 Flow Control
The chiller negates the Chiller RTS (output from Chiller) line whenever the Chiller is busy in a non-
interruptible process. The Chiller ignores the Host CTS line. No software (Xon/Xoff) flow control is
provided. It is the responsibility of the host to issue only a single command for which a response from
the Chiller Control is required until the response is received from the Chiller Control. Inter and intra
message timeout is defined as 1 second. (Typical response times and character pacing will be baud
rate limited.)
1.3 Encoding
All characters are to be ASCII characters. All messages from the host to the control and from the
control to the host will have 0x10 (ASCII Line Feed) as a start-of-message delimiter, and 0x0D
(ASCII Carriage return) as an end-of-message delimiter. Permitted message characters are in the
range of 0x20 through 0x7F (hexadecimal).
1.4 Numeric Representation
All numeric values will be represented by hexadecimal numbers, using ASCII characters ‘0’ – ‘9’ &
‘A’ – ‘F’. When multiple variables or parameters are returned by the Chiller Control they will be white
space separated (using ASCII 0x20). The host should recognize and use comma, tab and space as
white space characters.
1.5 Units
All temperature values will be communicated in two byte hex values of
Cx100 (.01 C
). Resolution
of temperature values is .1 degree. All pressure values will be communicated in integer psi with no
offset.
