ADLINK PCI-7856 User Manual
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16
Motionnet Master-Slave Motion System
RAM usage, users are able to write data into a FIFO in the central
device, and issue a send command using the same method. This
communication will be sent and received automatically by inter-
rupting the cyclic communication. A complete command delivering
time depends on the number of MNET packets. One packet com-
mand can be delivered in one MNET scan (cycle) time.
Command Delivery
For command delivery procedures which are transferred, in a
cyclic communication, the time allowed for communication by a
single module is fixed. However, in a data communication, the
communication time will vary, depending on how the communica-
tion is controlled by the user's program and the time needed to
access the PCI-7856. We will skip these elements and simply cal-
culate the basic data communication time in this section.
64(max)
4
Interrupt
Cyclic communication
1
2
3
5
Send
Response
Total of send and receive: 4 bytes
Data communication
Communication sequence image
(Send, Receive)
Center
Local
Local
Center