User Manual

<Appendix 4. PID Block>
A4-2
IM 01C50T02-01E
A4.3 Parameters of PID Block
NOTE: In the table below, the Write column shows the modes in which the respective parameters can be
written. A blank in the Write column indicates that the corresponding parameter can be written in all
modes of the PID block. A dash (-) indicates that the corresponding parameter cannot be written in any
mode.
Index Parameter Name
Default
(factory setting)
Write Valid Range Description
0 Block Header TAG: “PID” Block Tag =
O/S
Same as that for an AI block.
1 ST_REV — Same as that for an AI block.
2 TAG_DESC (blank) Same as that for an AI block.
3 STRATEGY 1 Same as that for an AI block.
4 ALERT_KEY 1 1 to 255 Same as that for an AI block.
5 MODE_BLK
6 BLOCK_ERR — Same as that for an AI block.
7 PV — Measured value; the non-dimensional value
that is converted from the input (IN) value
based on the PV_SCALE values and ltered.
8 SP 0 AUTO PV_SCALE
±10%
Setpoint
9 OUT MAN Output
10 PV_SCALE 100
0
1133
1
O/S Upper and lower scale limit values used for
scaling of the input (IN) value.
11 OUT_SCALE 100
0
1342
1
O/S Upper and lower scale limit values used for
scaling of the control output (OUT) value to the
values in the engineering unit.
12 GRANT_DENY 0 AUTO Same as that for an AI block.
13 CONTROL_OPTS 0 O/S Setting for control action. See Section A4.13
for details.
14 STATUS_OPTS 0 O/S See Section A4.15 for details.
15 IN 0 Controlled-value input
16 PV_FTIME 2 AUTO Non-negative Time constant (in seconds) of the rst-order
lag lter applied to IN
17 BYPASS 1 (off) MAN 1, 2 Whether to bypass the control computation.
1 (off): Do not bypass.
2 (on): Bypass.
18 CAS_IN 0 Cascade setpoint
19 SP_RATE_DN +INF Positive Rate-of-decrease limit for setpoint (SP)
20 SP_RATE_UP -INF Positive Rate-of-increase limit for setpoint (SP)
21 SP_HI_LIM 100 PV_SCALE
±10%
Upper limit for setpoint (SP)
22 SP_LO_LIM 0 PV_SCALE
±10%
Lower limit for setpoint (SP)
23 GAIN 1 Proportional gain (= 100 / proportional band)
24 RESET 10 Integration time (seconds)
25 BAL_TIME 0 Positive Unused
26 RATE 0 Positive Derivative time (seconds)
27 BKCAL_IN 0 Read-back of control output
28 OUT_HI_LIM 100 OUT_SCALE
±10%
Upper limit for control output (OUT)
29 OUT_LO_LIM 0 OUT_SCALE
±10%
Lower limit for control output (OUT)
30 BKCAL_HYS 0.5 (%) 0 to 50% Hysteresis for release from a limit for OUT.
status
31 BKCAL_OUT 0 — Read-back value to be sent to the BKCAL_IN
in the upper block