T
HERMO
R
ACK
800
T
HERMOELECTRIC
C
HILLER
52-13007-1
S
OLID
S
TATE
C
OOLING
S
YSTEMS
,
167
M
YERS
C
ORNERS
R
OAD
,
W
APPINGERS
F
ALLS
,
NY
12590
18
T
ELEPHONE
:
(845)
296-1300
F
AX
:
(845)
296-1303
WEB
:
WWW
.
SSCOOLING
.
COM
V
ERSION
M8
7.2
RS-232
C
OMMUNICATIONS
O
PTION
The Thermorack 800 can come with optional RS-232 serial communications, instead of the standard USB,
that can receive a remote set point, return the current temperature, and signal an alarm has occurred. The
commands are identical to USB and the protocol is shown below.
Wiring:
Proper wiring depends upon whether the equipment being cooled (the Host) is wired as Data
Computer Equipment (DCE) or Data Terminal Equipment (DTE)
Table 1A: Signal definition and wiring for Host wired as DTE
Computer/Host/Master
Male 9-Pin D-sub Pin #
Chiller / Slave
Female 9-Pin D-sub Pin#
2 (Receive – RXD)
2 (Transmit – TXD)
3 (Transmit – TXD)
3 (Receive – RXD)
5 (Ground)
5 (Ground)
Note: Use a null modem cable if your RS-232 is set up as a DCE.
Communication Specification
Speed:
9600 baud
Data Flow Control:
None
Data Format:
8-bit serial
Number of Start bits
1
Number of Stop bits:
1
Parity:
None
Master/Slave:
The Thermorack 800 is always the SLAVE (DTE)
Interrupts Reported:
None, must be polled for status
Transmission Length:
< 15 meters
Data Update Frequency:
Once per second
Maximum Polling Frequency:
One command every 500msec
Data Format:
ASCII
Insert a carriage return (0x0D
hex
) at the end of each command string.
A carriage return (0x0D
hex
) is sent at the end of each response
Female DB9
