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 Special Memory Bytes SMB86 to SMB94, and SMB186 to SMB194
Port 0 Port 1
SMB86 SMB186
SMB87 SMB187
SMB88 SMB188
SMB89 SMB189
SMW90 SMW190
SMW92 SMW192
SMB94 SMB194
490
Description
Receive Message status byte
MSB
7
n r
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
Receive Message control byte
MSB
7
en sc
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.
Start of message character
End of message character
Idle line time period given in milliseconds. The first character received after idle line
time has expired is the start of a new message.
Inter-character/message timer time-out value (in milliseconds). If the time period is
exceeded, the receive message is terminated.
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.
e 0 0 t c
ec il c/m tmr bk
LSB
0
p
LSB
0
0