Toshiba DeviceNet nv Series, Инструкция по эксплуатации, Страница: 59 / 159

4.2 Controller Interface Buffer Memory Configuration
Unified Controller nv Series DeviceNet Module DN611B Instruction Manual
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6) How to use semaphore area
Figure 4 3 shows how to use the various areas/registers described in 1) ~ 5). The shaded area in the figure
indicates the state where each flag register is "1" and the request register is "256".
a) Read the acknowledgment flag register with the MREAD instruction and confirm that it is "0".
b) Write the request data to DN611B in the request area with the MWRITE instruction (0334H is the
beginning).
c) Write "1" to the request flag register by MWRITE instruction.
d) Write "256" to the request register by the MWRITE instruction.
e) Read the acknowledgment flag register with the MREAD instruction and wait until it becomes '1'.
f) Read out the response data of DN611B from the acknowledgment area with the MREAD instruction when
the acknowledgment flag register becomes "1" (02D0H is the first).
g) Write "0" to the acknowledgment flag register with the MWRITE instruction.
Return to b)
Figure 4-3 How to use semaphores for requests
7) Precautions in using the semaphore area
- Please issue the next request after the acknowledgment of DN611B for one request from the controller
returns because there is only one set of request area and acknowledgment area.
- Do not write data (MWRITE instruction) to the acknowledgment area. The response data may be corrupted.
- When writing data to the request area by the MWRITE instruction, pay attention to the first address of the
area and the amount of data to be written. The DN611B may malfunction by destroying the data in other
areas.
Controller
Request flag
register
Request
register
Acknowledgement
flag register
DN611B
Request Area
Write
Requested
Request notice
DN611B
processing
Acknowledgement
area read
Request Area Read
Acknowledgment area write
Completion of
request area read
Responded
Acknowledgement
flag register read
Completion of
acknowledgement
area read