Siemens CP 243-2 User Manual

Interface to the User Program in the S7-200 CPU

2-11

SIMATIC NET CP 243-2 AS-i Master
C79000-G8976-C142/02

The user program controls the data exchange with the CP 243-2 using this
register.

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Table 2-2

 

BS0..BS5

0 ... 63

dec.

Bank select bits for changing the bank in the analog module
(see Section 2.5).

ASI_COM

0/1

Job bit for the AS-i command interface (see Section 5.1).

PLC_RUN

In the STOP mode of the S7-200 CPU, the CP must send defined values to
all AS-i slaves (see Chapter 3). Since the AS-i slave data are transferred
via the analog area and the S7-200 CPU does not set this area to ’0’ when
it changes from RUN to STOP, the CPU mode must be signaled to the
CP 243-2 using the PLC_RUN bit as follows:

0

Signal to the CP 243-2 that the S7-200 CPU is in the STOP
mode. 

The CP 243-2 sends ’0’ to all AS-i binary slaves. The analog
value transfer to analog output slaves is interrupted. The
S7-200 CPU sets the bit automatically to “0” at a change from
RUN to STOP.

1

Signals to the CP 243-2 that the S7-200 CPU is in the RUN
mode. 

The CP 243-2 sends the content of output bank 0 to all AS-i
slaves (see Section 2.4). The user program must set this bit to
“1” during startup (first scan).