Specifications

Special Memory (SM) Bits
C-12
S7-200 Programmable Controller System Manual
C79000-G7076-C233-01
Table C-15 Special Memory Bytes SMB66 to SMB85
SM Byte Description
SM76.6 PTO1 pipeline overflow (cleared by the system when using external profiles,
otherwise must be reset by the user); 0 = no overflow, 1 = pipeline overflow
SM76.7 PTO1 idle bit: 0 = PTO in progress, 1 = PTO idle
SM77.0 PTO1/PWM1 update the cycle time value: 1 = write new cycle time
SM77.1 PWM1 update the pulse width value: 1 = write new pulse width
SM77.2 PTO1 update the pulse count value: 1 = write new pulse count
SM77.3 PTO1/PWM1 time base: 0 = 1 µs/tick, 1 = 1 ms/tick
SM77.4 Update PWM1 synchronously:
0 = asynchronous update, 1 = synchronous update
SM77.5 PTO1 operation: 0 = single segment operation (cycle time and pulse count
stored in SM memory), 1 = multiple segment operation (profile table stored in
V memory)
SM77.6 PTO1/PWM1 mode select: 0 = PTO, 1 = PWM
SM77.7 PTO1/PWM1 enable bit: 1 = enable
SMB78
SMB79
PTO1/PWM1 cycle time value (2 to 65,535 units of the time base);
SMB78 is most significant byte, and SMB79 is least significant byte.
SMB80
SMB81
PWM1 pulse width value (0 to 65,535 units of the time base);
SMB80 is most significant byte, and SMB81 is least significant byte.
SMB82
SMB83
SMB84
SMB85
PTO1 pulse count value (1 to 2
32
-1);
SMB82 is most significant byte, and SMB85 is least significant byte.
SMB86 to SMB94, and SMB186 to SMB194: Receive Message Control
As described in Table C-16, SMB86 through SMB94 and SMB186 through
SMB194 are used to control and read the status of the Receive Message
instruction.
Table C-16 Special Memory Bytes SMB86 to SMB94, and SMB186 to SMB194
Port 0
Port 1 Description
SMB86 SMB186
7
MSB LSB
nre00tcp
0
Receive Message status byte
n: 1 = Receive message terminated by user disable command
r: 1 = Receive message terminated: error in input parameters or
missing start or end condition
e: 1 = End character received
t: 1 = Receive message terminated: timer expired
c: 1 = Receive message terminated: maximum character count achieved
p 1 = Receive message terminated because of a parity error