A5.10 Bumpless Switching; A5.11 Setpoint Limiter; A5.11.1 When Pid Block Is In Auto Mode; A5.11.2 When Pid Block Is In Cas Or Rcas Mode - YOKOGAWA Admag TI Series User Manual

Note 2: A transition to Cas, RCas, or ROut requires that initialization of the cascade connection
has been completed.
Note 3: I n case of the mode shedding (the data status of RCAS_IN, ROUT_IN is BAD), it
transitions to the mode which has been specified with SHED_OPT. (For details, refer to
A5.17.1.)

A5.10 Bumpless Switching

Bumpless switching is the function to allow the bumpless switch of MODE_BLK and of operation
output values at the cascade downstream without a sudden change in the control output.
The action to perform a bumpless switching differs depending on the MODE_BLK values.

A5.11 Setpoint Limiter

The setpoint limiter function is to limit the settings of the setpoint (SP).
The operation of the setpoint limiter differs based on the block mode of the function block.
A5.11.1 When PID Block Is in Auto Mode
When the block mode (MODE_BLK) is Auto, the limiters of the setpoint (SP) in force are high/low
limit and change-rate limit.
A5.11.1.1
A value exceeding the set high limit (SP_HI_LIM) cannot be set for SP.
A value smaller than the set low limit (SP_LO_LIM) cannot be set for SP.
A5.11.1.2
The change-rate limits are used to restrict the magnitude of changes in the SP value so as to
change the SP value gradually towards a new setpoint.
The increase of the SP value at each execution period of PID (period of execution in the Block
Header) is limited to the value of SP_RATE_UP or less.
The decrease of the SP value at each execution period of PID (period of execution in the Block
Header) is limited to the value of SP_RATE_DOWN or less.
A5.11.2 When PID Block Is in Cas or RCas Mode
By selecting Obey SP Limits if Cas or RCas in CONTROL_OPTS (see Subsection A5.13.1), the
setpoint (SP) high/low limits can be put into force when the block mode (MODE_BLK) is Cas or
RCas.
High/Low Limit
Change-rate Limit
<Appendix 5. PID Block>
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