Siemens SIMATIC S5 Manual page 116

Byte 27 Main control byte 1
Bit 0 If the actual value indication is unsteady, a filter can be looped into the indication
processing. Bit 0 = 0
Bit 1 Heating current monitoring (see Section 3.3)
Bit 2 If this bit is set, two parameter sets can be used for each controller, e.g. separate
parameters can be set for cooling.
and:
The controller parameters can be read in and out by the function block; i.e. the
parameters calculated by the self-tuning function can also be read into the CPU
and saved.
2
If Bit 2 = 0, the self-tuning function is started and stopped via byte 22, Bit 2
(self-tuning parameter). This corresponds to the functionality of the IP 244
version -3AA13 with the old FB 162 (32 messages).
2
If Bit 2 = 1, the self-tuning function is started and stopped via byte 22, Bit 2
upward and downward edges. These edges are generated by the new FB 162 (64
messages) for each controller separately via the command "SE".
Bit 3 Selection of the special function for reading in measured values.
Bit 4 If this bit is set, the hot channel control (see Section 3.1) is activated.
Bit 5 Enables cascaded control (see Section 3.2).
IP244
C79000–B8576–C860–02
Data Exchange with the Central Controller
filter on (damped display)
1
7
using
4–49