Table of Contents
Advertisement
Analog Value Processing
Scanning in the case of the 460 module
The 460 module has two different methods of coding analog values using a toggle switch.
Cyclic scanning:
With this function, the module itself handles the coding of all inputs. Coding time in the case of
the 460 analog input module is 480 ms.
The digitized measured values are stored in the circulating buffer under the channel-specific
address (the high byte under address n, the low byte under address n+1). The measured values
can then be read out of the circulating buffer at any time.
Selective scanning:
Coding of the desired analog variable is initiated by the user program. Coding time begins when
the module is referenced. FB 250 sets the TBIT to "1" during coding and no further access may
occur while coding is in progress.
6.6
Analog Output Modules
6.6.1
Method of Operation of the Analog Output Modules
The CPU processes the digital values which the analog output modules will convert to the required
currents and voltages. Different floating modules cover the individual voltage and current ranges.
The CPU transfers the digital value to the module memory. The last coded value is retained in the
analog output module even after PLC STOP.
Transfer of the coded value is started by FB 251 ANAU.
6-28
S5-115F Manual
EWA 4NEB 811 6148-02
Advertisement
Table of Contents
