Smb86 To Smb94, And Smb186 To Smb194: Receive Message Control - Siemens Simatic S7-200 System Manual

S7-200 Programmable Controller System Manual

SMB86 to SMB94, and SMB186 to SMB194: Receive Message Control

As described in Table D-16, SMB86 through SMB94 and SMB186 through SMB194 are used to control
and read the status of the Receive Message instruction.
Table D-16
Port 0
SMB86
SMB87
SMB88
SMB89
SMW90
SMW92
SMB94
D
416
Special Memory Bytes SMB86 to SMB94, and SMB186 to SMB194
Port 1 Description
SMB186 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
SMB187 Receive Message control byte
en: 0 =Receive Message function is disabled.
1 =Receive Message function is enabled.
The enable/disable receive message bit is checked each time
the RCV instruction is executed.
sc: 0 =Ignore SMB88 or SMB188.
1 =Use the value of SMB88 or SMB188 to detect start of message.
ec: 0 =Ignore SMB89 or SMB189.
1 =Use the value of SMB89 or SMB189 to detect end of message.
il: 0 =Ignore SMW90 or SMW190.
1 =Use the value of SMW90 or SMW190 to detect an idle line condition.
c/m: 0 =Timer is an inter-character timer.
1 =Timer is a message timer.
tmr: 0 =Ignore SMW92 or SMW192.
1 =Terminate receive if the time period in SMW92 or SMW192 is exceeded.
bk: 0 =Ignore break conditions.
1 =Use break condition as start of message detection.
SMB188 Start of message character
SMB189 End of message character
SMW190 Idle line time period given in milliseconds. The first character received after idle line time has
expired is the start of a new message.
SMW192 Inter-character/message timer time-out value (in milliseconds). If the time period is exceeded,
the receive message is terminated.
SMB194 Maximum number of characters to be received (1 to 255 bytes).
Note: This range must be set to the expected maximum buffer size, even if the character count
message termination is not used.
MSB
7
n r e 0 0
MSB
7
en sc ec il c/m
LSB
0
t c p
LSB
0
tmr bk 0