Appendix; A Notes On Operating The Ip 244 With The Self-Tuning Function; Requirements; Recommended Procedure For Single Self-Tuning Function - Siemens SIMATIC S5 Manual

Appendix

A Notes on Operating the IP 244 with the
Self-Tuning Function with FB 162 for
64 Messages
A.1 Requirements
A.1.1 Controlled System
– The controlled system must permit a physical setpoint jump of 37 C for 2-step
controllers or up to 110 C for 3-step controllers.
– The controlled system must demonstrate low pass characteristics.
– The rate of rise of the actual value must not exceed maximum 60 C/min at full
heating power or when simultaneously heating and cooling or the actual value may
not fall more than 60 C/min.
– The maximum rise of the actual value must be
power.
– The heating procedure must not take longer than 12 hours.
With pure Pt 100 operation only 11.6 h is permitted.
and ADC conversion time = 50 ms, only 7.2 h permitted
and ADC conversion time = 60 ms, only 8.7 h permitted
– If only the cooling is active, you must guarantee that the actual value falls.
– Suitable for systems in which no very large step-like disturbances (in the
automation control sense) occur.
A.1.2 Parameter Assignment
– Main control byte 1, bit 2 = 1
– DL n + 11, bit 1 = 1
– Controller has heating output
– No hot channel controller
– No master controller with cascaded control
A.2 Recommended Procedure for Single Self-Tuning Function
A.2.1
All the parameters not marked with "ST" in messages 0 to 12 and 30 to 42 must have
values assigned and the controller must be disabled using setpoint 0 or by setting the
heating switch to "Off". This prevents an unnecessary heating up before the
self-tuning function is started.
A.2.2
Generate an upward edge in bit 7 in the data byte n + 11 by means of the commands
"ST", "CR" or "PA". (The user must make sure to allocate the data byte DLn + 11
correctly.)
IP244
C79000–B8576–C861–02
Appendix
0.05 C/min with full heating
5–59