Data format:
Baud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1200
Data bits . . . . . . 8 (7 bit ASCII with leading zero)
Start bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Stop bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Parity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . none
The data transfer sequence is transmitted in the following format. X refers
to numerical temperature data.
(NUL) (-) XXX (SP) C (SP) (Error Message) (SP) (LF) (CR) (EOT) (SP)
In the event of a CNTRLFAIL, Er07, or the control probe is out of range
error, the numerical temperature data (XXX) in the transmission would be
replaced by T_ERR.
If no alarm condition exists, spaces will be sent. A total of 20 characters
will be sent.
SP - Space LF - Line feed
CR - Carriage return EOT - End of text (4)
NUL - Null character (00)
If an alarm condition does exist, “Error Message” in the protocol will be
replaced by the following:
UNDERTEMP (temperature above the low alarm setpoint)
OVERTEMP (temperature below the high alarm setpoint)
PWRFAIL (AC power failure)
CNTRLFAIL (Control probe failure)
Er07 (micro failure)
HSHX FAIL (Heat exchanger failure)
HOT COND (Hot condenser)
See Figure 1-2 for the location of the remote alarm contacts. The remote
alarm connector is located in the parts bag provided with the manual. It
must be installed if connecting the
freezer to an alarm system. After
installing the wiring from the alarm
system to the connector, install the
connector to the freezer microboard
and secure with the two screws
provided. The remote alarm provides a
NO (normally open) output, a NC
normally closed) output and COM
(common). The contacts will trip on a
Model 900 and 5900 Series 1-7Thermo Scientific
Section 1
Installation and Start-Up
Remote Alarm Contacts
RS-232 Communications
(continued)
Figure 1-8. Remote Alarm Contacts
IMPORTANT USER INFORMATION
CAUTION! Stored product should be protected
by a redundant 24 hour/day monitoring system
with alarm capability. An interconnect jack and
thermocouple are installed for centralized
monitoring, should on-board system fail.