Low Speed Cyclic Transmission - Mitsubishi Electric MELSEC iQ-R Series User Manual

Low speed cyclic transmission

The low speed cyclic transmission function collectively sends the data that does not require high-speed performance to
another station by link devices (LB, LW) to share the data between modules.
It has the same performance as the transient transmission function. (Page 34 Transient Transmission Function)
The number of transmissions per station during one link scan is one.
When data is simultaneously sent from multiple stations, a link scan time of at least the number of sending stations is
required.
Setting the send range
Assign the send range of link devices (low speed LB, low speed LW) at each station to the extended function area (2000H to
3FFFH) in units of 16 points for LB and in units of 1 point for LW. The send range that is not in station number order can be
also assigned for each station. There are no device numbers that can be assigned to the device (B, W) of the CPU module
corresponding to the extended function area.
0H
CPU module B
RJ71LP21-25 LB
(1) Normal cyclic transmission area
(2) Extended function area
• When using 32-bit data, set the number of send points and send range so that the execution condition of 32-
bit data assurance is satisfied. (Page 30 32-bit data assurance)
• The number of device points (B, W) for the CPU module can be changed by the CPU parameter. (
MELSEC iQ-R CPU Module User's Manual (Application))
• The link device for the extended function area (2000H to 3FFFH) is also used for normal cyclic
transmission. (When using 8193 or more link devices for normal cyclic transmission) For link devices for low
speed cyclic transmission, use link devices in the extended function area that is not used for normal cyclic
transmission.
• The total send range per station for low speed cyclic transmission should be 2000 bytes or less. (The send
range of normal cyclic transmission is not included.)
• The link devices for low speed cyclic transmission are only LB and LW.
1 FUNCTIONS
20
1.1 Cyclic Transmission Function
2000H
(8192)
(1)
3FFFH
(16383)
(2)