Rockwell Automation 1203-SM1 SLC to SCANport Communication Module - Manual (Page 40)

4–12 Using Enhanced Mode
Publication 1203–5.9 –– October 1996
The M0 file image contains multiple transmit message buffers set up
as shown in Figure 4.9.
Figure 4.9
M0 File Structure
Service
Class
Instance
Attribute
Request Length = n
Req Data 2
Req Data n
Req Data 1
...
M0:e.000
M0:e.001
M0:e.002
M0:e.003
M0:e.004
M0:e.005
M0:e.0xx
Service
Class
Instance
Attribute
Request Length = n
Req Data 2
Req Data n
Req Data 1
...
M0:e.400
M0:e.401
M0:e.402
M0:e.403
M0:e.404
M0:e.405
M0:e.4xx
Service
Class
Instance
Attribute
Request Length = n
Req Data 2
Req Data n
Req Data 1
...
M0:e.100
M0:e.101
M0:e.102
M0:e.103
M0:e.104
M0:e.105
M0:e.1xx
Service
Class
Instance
Attribute
Request Length = n
Req Data 2
Req Data n
Req Data 1
...
M0:e.500
M0:e.501
M0:e.502
M0:e.503
M0:e.504
M0:e.505
M0:e.5xx
Service
Class
Instance
Attribute
Request Length = n
Req Data 2
Req Data n
Req Data 1
...
M0:e.200
M0:e.201
M0:e.202
M0:e.203
M0:e.204
M0:e.205
M0:e.2xx
Service
Class
Instance
Attribute
Request Length = n
Req Data 2
Req Data n
Req Data 1
...
M0:e.600
M0:e.601
M0:e.602
M0:e.603
M0:e.604
M0:e.605
M0:e.6xx
Service
Class
Instance
Attribute
Request Length = n
Req Data 2
Req Data n
Req Data 1
...
M0:e.300
M0:e.301
M0:e.302
M0:e.303
M0:e.304
M0:e.305
M0:e.3xx
Service
Class
Instance
Attribute
Request Length = n
Req Data 2
Req Data n
Req Data 1
...
M0:e.700
M0:e.701
M0:e.702
M0:e.703
M0:e.704
M0:e.705
M0:e.7xx
Message Buffer 0
Message Buffer 1
Message Buffer 2
Message Buffer 3
Message Buffer 4
Message Buffer 5
Message Buffer 6
Message Buffer 7
e = slot location
The M0 file contains eight separate buffer areas. Each area can be
used to send messages to any of the three channels. You need to
access a unique area of the M0 files for each message buffer used.
Individual message request status bits (located in Word 1 of the I/O
input image) are used to monitor the progress of each message
request enabled. The Message ID selection field and Message
Enable bits (located in Words 0 and 1 of the I/O output image)
initiate each message transaction and subsequently free the receive
buffer for the next message.