Red Lion TCU - Manual (Page 32)

On models equipped with Second Analog Input, configured as Remote
Setpoint, this parameter may be used to establish a maximum rate of change of
the Remote Setpoint reading. If the controller or transmitter that supplies the
Remote Setpoint reading is swinging too wildly, or changing too fast,
resulting in control problems, the ramp rate can be used to reduce the rate of
change of the Remote Setpoint reading. When ramping in Remote Setpoint
operation, the flashing decimal point is suppressed. The units of ramping for
Remote Setpoint operation are 0.1 to 999.9 LSD/minute.
User Input
The user input may be programmed to perform a variety of controller
functions. The input must be in its active state for 100 msec minimum to
perform the function. The unit executes all functions in 100 msec, except the
print request function that requires 110 to 200 msec for a response. A function
is performed when the User Input, (Terminal 7) is used in conjunction with
common (Terminal 10).
Note: Do not tie the commons of multiple units to a single switch. Use either a
multiple pole switch for ganged operation or a single switch for each unit.
Below is a list of the available functions.
PLOC - Program Lock. A low level enables the program disable function
which places the unit in the Protected Parameter Mode.
Note: Front panel disable is possible without using this program lock
function, see
Front Panel Program Disable , page 12.
ILOC - Integral Action Lock. A low level disables the integral action of the
PID computation. A high level resumes the integral action.
trnF - Auto/Manual Transfer. A negative transition places the unit in the
manual (user) mode and a positive transition places the unit in the
automatic operating mode. The output is “bumpless” when transferring to
either operating mode.
SPrP - Setpoint Ramp. A low level terminates setpoint ramping and the
controller operates at the target setpoint. Terminating setpoint ramping is
the same as setting the ramp rate to zero (SPrP = 0.0). A high level enables
the programmed setpoint ramp rate.
ALrS - Alarm Reset. If the alarm option is installed, a low level resets the
alarm(s) to their inactive state as long as the user input is low.
Prnt - Print Request. A low level transmits the print options selected in the
serial communications module (6-SC). If the user input is held low, after
the printing is complete a second print request is issued.
SPSL - Select Local or Remote Setpoint. On models equipped with Second
Analog Input, configured as Remote Setpoint, a negative transition
engages Remote Setpoint operation and a positive transition engages
Local Setpoint operation. Select the controller output response to the
Local/Remote transfer operation (bumpless, tracking, etc) by the setpoint
transfer parameter (SPtr).
Heater Current Monitor Scaling (HCur) (Optional)
Enter the full scale rating of the current transformer used with the
controller. This scales the Heater Current Monitor of the controller to
indicate directly in amperes of heater current.
HCur - 0.0 to 999.9 amperes (normally 50.0)
Alternatively, the Heater Current Monitor may be scaled to indicate in
percent of nominal heater current (0.0 to 100.0%). This may be useful in
applications employing several controllers, each with nominal heater current
readings that are different from each other. In this case, each controller can be
scaled to indicate the same reading (100.0%), independent of each
controller’s actual heater current. For example, if using a 50 ampere current
transformer and the actual heater current is 38 amperes, the Heater Current
Monitor scaling value is:
HCur
Amperes
Amperes
= =
50 0
38 0
100 0 131 6
.
.
. % . x
This scaling value results in a Heater Current Monitor indication of
100.0% at an actual heater current of 38 amperes.
See Alarm Action , page 29, to program a Heater Break Alarm.
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