Reading Theanalogvalue - Siemens SIMATIC S5 1P 243 Equipment Manual

Programming Instructions
7.4.6 Reading the Analog Value
The channel numbers from O to 7 are specified via the parameter BGKN of function block FB 160.
The LEDs on the module's front plate indicate the currently selected channel as a bit pattern.
The analog value read in the example is transferred to the module through the front panel connec-
tor via input IW1 (contact 24) and the appropriate potential contact (contact 23). It can be meas-
ured simultaneously at sockets 1 (IW1) and 6 (ManJ. The output for analog value acquisition AV1
(Pin 16) must be brought to channel O of the ADC (Pin 1) via analog value jumpering.
The analog value read by function block FB 160 is output in flag word FW 10. Via the programmer
function "Control Variable", the actual value can be displayed directly.
If input 14.0 ("NORM") is brought to switch position"1", the analog value is displayed in mV given
in binary code (ranging from –1 0000 to +10000). Othetwise it is given as a bit pattern, the way it
arrives from the module.
Via the two potentiometers "Work point AV1" and "Amplification AV1", the analog value can be
changed. In order to check whether the module reproduces the applied value in correct form, the
amplification should be set to value"1" and the work point to "O". For this purpose a firm value
(e.g., 2 V) should be specified at the analog value input AV1. Then a reading should be taken at the
sockets and the amplification changed until the input value matches the end value. The work point
is set by zero adjustment (i.e., the applied and the measured voltages are both zero). Via soldered
jumpers the individual voltage ranges can be set as follows:
7 – 16
R 02/92