Constant Link Scan; Data Assurance - Mitsubishi Electric MELSEC iQ-R Series User Manual

Constant link scan

If the network status is unstable, the link scan time can be kept constant by specifying the link scan time at the control station
to allow for possible fluctuations in the link scan time.
For the setting method, refer to the following.
Page 65 Supplementary Cyclic Settings

Data assurance

This function assures the cyclic data in units of 32 bits or station-based units.
The following three methods are available for cyclic data assurance.
Method
32-bit data assurance
Assurance of data of more
than 32 bits
Link scans are performed asynchronously with link refresh.
Therefore, when the following cyclic data of 32 bits or more are handled, new and old data may be mixed in
units of 16 bits depending on the link refresh timing.
• Floating-point data
• Present value or command speed value of a positioning module
32-bit data assurance
The link relay (LB) and link register (LW) data can be assured in units of 32 bits.
When LB and LW are set with the following four conditions met, 32-bit data assurance is automatically assured.
• The start device number of LB is a multiple of 20H.
• The number of points assigned per station in LB is a multiple of 20H.
• The start device number of LW is a multiple of 2.
• The number of points assigned per station in LW is a multiple of 2.
Set LB and LW under "Network Range Assignment" in "Required Settings" of the control station. (Page 55 Network
Range Assignment)
If the network is configured with the MELSECNET/10 mode, 32-bit data assurance is disabled for the ACPU/
QnACPU installed stations. Configure an interlock by the program for the ACPU/QnACPU installed stations.
( Page 79 Precautions for Programming)
1 FUNCTIONS
30
1.1 Cyclic Transmission Function
Description
Assures data in 32-bit units. Data is automatically assured by satisfying assignment conditions of
link devices.
Station-based block data Assures data in station-based units. Data is assured by enabling the send/receive data station-
assurance based block data assurance in the parameter setting.
Interlock program Assures data of more than 32 bits. Data is assured by configuring interlocks on programs.