Byte 0: Mode; Byte 1: M Function - Siemens SIMATIC S5 Manual

Communication Between the CPU and the IP 266
7.2.1

Byte 0: Mode

The IP 266 acknowledges the mode in byte 0. This value can be read in KF (fixed-
point constant) format.
Example:
The IP 266 returns the mode that is currently in progress or was just executed in
byte 0 of the input frame.
The current mode is mode 2 (JOG 2).
Note:
Neither the current monitoring mode (71, 72 or 73) nor mode 99, which
synchronizes the IP 266, is acknowledged.
7.2.2

Byte 1: M Function

In modes 8 and 9, the drive is positioned via machining programs. If M functions
were written in these programs, their values are entered in byte 1 when the
relevant machining block is processed. The value is best read out in KF format.
Value range of Mnn:
Example:
The IP 266 returns the following in byte 1:
An M50 function has been written in the machining program.
7-14
KF = +2
nn is a two-digit number in the range 00 to 99. If no M func-
tion is programmed, the IP 266 forwards the three-digit
number "255" to the COM program (PLC format KH: "FF";
format KF: "- 1").
KF = +50
IP 266
EWA 4NEB 812 6057-02