Mitsubishi Electric Melsec QJ71LP21 Reference Manual page 169

5 PARAMETER SETTINGS
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3) Constant scan
The constant link scan function is used to maintain the link scan time
constant.
Set a value in the following range to use a constant scan time:
Setting time
Blank
1 to 500 ms
4) Maximum No. of return to system stations in 1 scan (Refer to Section
3.2.2)
Set the number of faulty stations that can return to the network in one
link scan.
• Valid number of stations : 1 to 64 stations
• Default
5) With multiplex transmission (Refer to Section 7.6)
Set this item when executing the multiplex transmission function.
The multiplex transmission function is used when both the forward and
reverse loops are in the normal status to speed up the transmission
rate using both loops at the same time.
• Default: No multiplex transmission
6) There is a data link through the sub-controlling station when the
controlling station is down (Refer to Section 3.2.2)
Set this item to enable other normal station in the network to continue
cyclic transmission as a substitute station (sub control station) (control
station shift function) if the specified control station is cut off from the
network due to an error.
• Default: Control station switch function enabled
7) Block send data assurance per station/Block receive data assurance
per station (Refer to Section 6.2.2)
Set these items when executing the link data separation prevention
per station in the cyclic transmission.
This allows multiple word data manipulation without interlocks.
However, the separation prevention
processing between the CPU module and the network module.
The default varies depending on the network type.
Network type
MELSECNET/H mode
MELSECNET/10 mode
MELSECNET/H Extended mode
1: The separation prevention refers to a prevention of link data with
double word precision (32 bits), such as the current value of the
positioning module, from being separated into new data and old
data in one word (16 bits) units due to the cyclic transmission
timing.
Constant scan
Not executed (default)
Executed using the set time
: 2 stations
1 is valid only for the refresh
"No" for both send and receive
"Yes" for both send and receive
MELSEC-Q
Default
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