Yaskawa MP940 Reference Manual - Manual (Page 104)

MotionSuite™ MP940 Machine Controller Reference Manual Serial Transmission Function
4-13
Time Needed for Transmission
The types and content of the time needed for signal transmission between
master and slave using the Memobus protocol as an example are described
below.
Outline
The time needed for signal transmission between master and slave in a
Memobus system can be calculated.
• Transmission processing time for command messages by the
master
• Modem delay time on master side
• Command message transmission time
• Slave processing time
• Modem delay time on slave side
• Response message transmission time
• Transmission processing time for response messages by the
master
For total time needed when a number of slaves are connected to the same
master port, calculate the time needed for each slave, and use the sum
thereof.
Scale of time needed by external units
Each of these times is described in detail below.
Transmission processing time for command messages by the master
• Time until the PC sends the command message into the Memobus port.
• This time depends on each of the master processing times. (This is normally
1 scan, and depends on the machine controller scan time.)
Modem Delay Time on Master Side
• This is the time which transpires between the receipt of a Request Transmis-
sion Signal (RTS) by the modem, and the Confirm Transmission Signal
(CTS) return to the master.
• This can be ignored if a Yaskawa modem is used, because this time is 5ms or
less. This delay time does not exist if no modem is used.