Siemens SIMATIC NET CP 243-1 IT Technical Manual page 124

Example
LD
CALL
Symbol Address
SM0.0
Always_On
MW8
ch_ready
MW2
cp_error
M0.0
cp_ready
SBR1
ETH0_CTRL
NETWORK 2
As soon as channel 0 is ready for the transmission and "ch0_ready" is set, the
variable "start" is set. This may take several cycles.
LD
S
Symbol Address
M8.0
ch0_ready
M4.0
start
NETWORK 3
For an S7-200, the "First_Scan_ON" bit is anly set in the first cycle for systemre-
lated reasons. Thus, the "start" variable is reset. This procedure is required so that
the "start" variable always generates a switching edge for the start of the
ETHx_XFR subroutine, even for repeated start/stop procedures of the CPU.
LD
R
Symbol Address
First_Scan_On SM0.1
M4.0
start
124
Always_On
ETH0_CTRL, cp_ready, ch_ready, cp_error
Always ON, always 1
This POU was generated by the Internet wizard for use for the
CP243-1 IT.
ch0_ready
start, 1
Bit for channel 0 in the return value CH_READY of the subroutine
ETH0_CTRL
Flip flop for automatic start of the data transmission
First_Scan_On
start, 1
ON for the first scan cycle only
Flip flop for automatic start of the data transmission
Comment
Comment
Comment
J31069-D0429-U001-A0-7618
03/03
CP 243-1 IT