Red Lion TCU - Manual (Page 43)

In practice with the cooling output, observe the controlled temperature
characteristics and if the temperature remains above setpoint with a sluggish
return, increase the cooling gain. Similarly, if the temperature drops too
sharply with an overall saw-tooth pattern, decrease the cooling gain. Alter the
heat-cool overlap until a smooth response in the controlled temperature is
observed during band transition.
Serial Communications Module (6-SC) (Optional)
When communicating with a TCU unit via the serial port, the data formats
of both units must be identical. A print operation occurs when the user input,
programmed for the print request function is activated, when a “P” command
is sent via the serial communications port, or after the time expires for the
automatic print rate, if enabled. Serial communication is covered in detail in
RS485 Serial Communications, page 48.
Baud Rate (bAUd)
The available baud rates are:
300, 600, 1200, 2400, 4800, or 9600
Parity Bit (PArb)
Parity can be odd, even, or no parity.
Address Number (Addr)
Multiple units connected on the same RS485 interface line must each have
a different address number. A value of 0 does not require the address specifier
command, when communicating with the TCU. The address numbers range
from 0 to 99.
Abbreviated or Full Transmission (Abrv)
When transmitting data, the TCU can be programmed to suppress the
address number, mnemonics, units, and some spaces by selecting YES. An
example of abbreviated and full transmission are shown below:
NO - 6 SET 123.8F Full Transmission
YES - 123.8 Abbreviated Transmission
Print Rate (PrAt)
The TCU can be programmed to automatically transmit the selected print
options at the programmed print rate. Selecting 0 (zero) disables the
automatic print rate feature.
PrAt - 0 to 9999 seconds
35
Figure 20, Heat/Cool Operation (db<0)