Control Word 0, bits 7 (DA - Derivative Rate Action bit) and 4 (RG - Reset and Gain Rate Enhancement bit)apply only to the SLC 5/03, SLC 5/04, and SLC 5/05 processors and to the MicroLogix 1500 controller.
(MicroLogix 1200 and 1500) In Relay ladder logic, access to the high word (Control words 18 and 20 are only allowed through a double word access of the low word.
When using the MicroLogix 1500 controller the following word/bit associations apply to the PD file layout. . Sub-elements 0 - 16, 21, and 22 are addressable by word and/or bit through relay ladder logic. Sub-elements 17 and 19 are addressable by double word and/or bit through relay ladder logic.
Control Block Layout:
_Bit #:_15_14_13_12_11_10__9__8__7__6___5__4__3___2__1__0
Word 0:EN____DN_PV_SP_LL_UL_DB_DA_TF_SC_RG_OL_CM_AM_TM
Word 1 PID Sub Error Code (MSB)
Word 2 Setpoint SP
Word 3 Gain Kc
Word 4 Reset Ti
Word 5 Rate Td
Word 6 Feed Forward Bias
Word 7 Setpoint Maximum (Smax)
Word 8 Setpoint Minimum (Smin)
Word 9 Deadband
Word 10 INTERNAL USE - DO NOT CHANGE!!
Word 11 Output Max
Word 12 Output Min
Word 13 Loop Update
Word 14 Scaled Process Variable
Word 15 Scaled Error SE
Word 16 Output CV% (0-100%)
Word 17 MSW Integral Sum 5/03/Micro 1500 MSW Integral Sum
Word 18 LSW Integral Sum 5/03/Micro 1500 LSW Integral Sum
Word 19 Altered Derivative Term (Low word)
Word 20 Altered Derivative Term (High word)
Word 21 Time of Last Update
Word 22 Setpoint Old Value