Siemens SIMATIC S5 Manual page 204

STAR :
STOP :
VORW :
RUCK :
UEBN :
The modes 18 and 19 permitted by FB 164 are acknowledged negatively by the IP247 on all four
pages, since these modes do not exist on the IP247.
On the data channel, the modes 1-16 are also negatively acknowledged.
Following a negative acknowledgement, the parameter PAFE is set in FBI 84. The SEND block
The monitoring function 72 permitted by FBI 64 is acknowledged negatively on all pages. The
monitoring functions 71 and 73 are also negatively acknowledged on the data channel.
Here, the PAFE parameter is set following a negative acknowledgement. The RECEIVE block
:
If the BCD parameter has the signal state"1", the variables actual position value and distance to
go are converted to a seven digit BCD number with sign. If the signal state is "O", these values
are output in binary.
In the BCD format a maximum +/- 9999999 (pm, 0.0001 in, 0.001 degrees) can be represented.
If one of these limits is violated, the output value (parameter output ANZG or the corresponding
data words) is output as a binary number.
If an error is made in the parameter assignment, the PAFE parameter has the signal state"1".The
error can be identified by the settings in
flag byte FY255
Siemens AG°C79000-B8576-C707 -01
These parameters represent the possible commands
and start the data transfer to the positioning
module on the positive-going edge O -->1, recognized by
FB164 by comparing the binary identifiers in the axis DB
The following data from the axis data block
aretransferred:
byte parameters (DR n),
word parameters (DW n+l ) and
double word parameters (DD n+3)
The Standard Function Block FBI 64
6-11