TRICONEX 3481 industrial control module
SCL_ function blocks provide a means to scale an analog signal. It will re-range a signal by using the range pointer to reference the function block with the original range. When the range pointer (input R) is not configured, the function block will not re-scale the input signal but will pass it directly to the output. The purpose, under this situation, would be to provide minimum and maximum scale, preferred decimal point position, and units for another block (e.g. operator display) to reference.
SEL_ function blocks can provide a high or low signal selection on the three input signals. Unused inputs will be set equivalent to the lowest real value when configured as a HI selector and to the highest real value when configured as a LO selector.
3.2.92 SETPT - Setpoint
SETPT function blocks can be used on a one per loop basis to permit operator adjustment of the controller setpoint within the loop. The on-line setpoint is adjustable, using the pulser knob, while.S is the displayed variable; unless the track command TC is high (1), at which time the setpoint will track the TV input. A setpoint ramping feature allows the setpoint to ramp to a TARGET value. The start of a ramp can be initiated using a communication command asserting input SR high (the ramp starts on a positive transition of the SR input), or using the RAMP ON/OFF function in the QUICKSET mode. Both ramp RATE and ramp TIME can be set in configuration. Firmware 1.30 and higher sets the USE RATE default to NO; earlier versions are set at YES. Setting configuration parameter USE RATE to YES will cause the setpoint to change at the rate setting and ignore a configured ramp time. The RTIME or RRATE, TARGET, and PU SETPT values can be set using the QUICKSET feature if the QUICKSET parameter is set to YES. The RG PTR, range pointer, parameter determines the normal operating range of the function block. If the pointer is not configured the block will use 0.00 to 100.00. The range of the setpoint block will be limited to -10% to 110% of the range parameter. If a range change is made the current setpoint, ramp rate, target setpoint, and power up setpoint will be moved to be the same % values within the new range. The setpoint block also has two inputs LU and LD that can be used to limit pulser changes in one direction. This can be used if another function block is limiting the setpoint and it is desired not to allow the operator to adjust the setpoint block to a value beyond the external limit. POWER UP - The function block can be configured to power up in various conditions during a warm start. If the PU LAST parameter is set to YES, the block will power up with the last setpoint. When SETPT does not power up in last position or on a cold start, it will power up using the PU SETPT parameter.
