Yokogawa RotaMASS 3-Series - Manual (Page 152)

APPENdIX 5. PId BLOCK
a-52 IM 01R04B05-00E-E 3rd edition July 30, 2010 -00 all Rights Reserved. Copyright © 2005, Rota Yokogawa
A5.9.1 Mode Transitions
transition
Destination
Mode
Condition
not
Conditions
1. If o/S is set in MoDE_
BLK.target (or if o/S is set in
target inside the resource
block)
2. If the specified condition is
met (see Section a5.14)
3. If track Enable is specified in
ContRoL_oPtS and the
value of tRK_In_D is true
4. If Man is set in MoDE_
BLK.target or if In.status
(input status) is Bad
5. If auto is set in MoDE_
BLK.target
- anD -
if In.status (input status) is
not Bad
6. If Cas is set in MoDE_
BLK.target
- anD -
if neither In.status (input
status) nor CaS_In.status is
Bad.
7. If RCas is set in MoDE_
BLK.target
- anD -
if neither In.status (input
status) nor RCaS_In.status
is Bad.
8. If Rout is set in MoDE_
BLK.target
- anD -
if Rout_In.status (input
status) is not Bad
9. If RCaS_In.status or Rout_
In.status is Bad (indicating a
computer failure; see Section
a5.17.1 for details)
not if
condition 1
is met
not if either
or both of
conditions 1
and 2 are met
not if any
one or more
of conditions 1
to 3 are met
not if any
one or more
of conditions 1
to 3 are met
not if any
one or more
of conditions 1
to 3 are met
not if any
one or more
of conditions 1
to 3 are met.
not if any
one or more
of conditions 1
to 3 are met.
o/S
IMan
Lo
Man
auto*
Cas* , **
RCas* , **
Rout* , **
In accordance
with the
SHED_oPt
setting
ta0507.EPS
* to activate mode transitions to auto, CaS,
RCaS, and Rout, the respective target
modes must be set beforehand to MoDE_BLK.
permitted.
** a transition to CaS, RCaS, or Rout requires
that initialization of the cascade connection has
been completed.
A5.10 Bumpless Transfer
Prevents a sudden change in the control output
out at changes in block mode (MoDE_BLK) and
at switching of the connection from the control
output out to the cascaded secondary function
block. the action to perform a bumpless transfer
differs depending on the MoDE_BLK values.
A5.11 Setpoint Limiters
active setpoint limiters that limit the changes in
the SP value, differ depending on the block mode
as follows.
A5.11.1 When PId Block Is in AUTO
Mode
When the value of MoDE_BLK is auto, the four
types of limiters are in force: high limit, low limit,
rate-of-increase limit, and rate-of-decrease limit.
Setpoint High/Low Limits
• a value larger than the value of SP_HI_LIM
cannot be set for SP.
• a value smaller than the value of SP_Lo_LIM
cannot be set for SP.
Setpoint rate Limits
the setpoint 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.
• an increase of the SP value at each execution
period (period of execution in the Block Head-
er) is limited to the value of SP_RatE_uP.
• a decrease of the SP value at each execution
period (period of execution in the Block Head-
er) is limited to the value of SP_RatE_DoWn.
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 Section a5.13.1), the
setpoint high/low limits can be put into force also
when the value of MoDE_BLK is CaS or RCaS.