T.4.3
Communication is slow
Is the traffic between the Display and
connected device heavy?
Cause
When the display unit tries to
read/write the address data of many connected devices
simultaneously, the traffic increases and the communication
requires more time. This may result in slow responses for switches
on the display unit or slow updates for Data Display values.
The GP communicates to /from the addresses used on the currently
displayed screen.
The communication is done on
all screens if the address is used by the system data area, alarm,
sampling, global D-script, global window, or logic program.
As a result, when the functions above use many addresses, the
communication may take longer.
Solution
-
As much as possible, reduce the number of parts
placed on each screen. Set up parts that are not used all the time
on a window, so they are called only when required.
 12.3 Displaying
Windows
-
As much as possible, reduce the number of addresses
used by alarms, sampling, global D-scripts, or global windows.
-
As much as possible, use consecutive addresses for
parts on the same screen.
-
Use the [LS Area] or [USR Area] addresses in the
display unit for data that does not have to be stored on the
connected device.
-
Reduce the number of addresses of the connected
device to which logic programs are set.
Is the
communication speed between the Display and connected device set to
low?
Cause
The communication becomes slow when the communication speed
between the GP and connected device is set to low.
Solution
If the communication speed is set to low, change the setting to
improve the speed according to the procedure described in the
following sections.
T.6 Errors displayed on a PC
5.3.14 System Settings
[Device/PLC] Settings Guide
After the communication speed is changed, the
project file must be transferred again. You also need to change the
communication speed of the connected devices accordingly.
Is the communication line affected by
noise?
Cause
If the communication line is affected by noise, the
communication appears to slow down because it is interrupted
frequently.
Solution
Monitor the value of the communication time and check the
communication line to confirm whether the communication line is
affected by noise.
-
Check the Communication Time (communication cycle
time)
Check the value of the communication time (communication cycle
time) stored in the LS Area of the display unit. The communication
time (communication cycle time) is stored in LS9400 of the LS Area
in millisecond units.
-
Open the
project file currently being used, and place the Data Display
specifying LS9400 on all screens.
-
Transfer the project file to the GP again.
-
Monitor this value on the display unit screen.
If the value of LS9400 increases at specific occasions, a
communication error is occurring due to noise or other causes.
-
When two or more
devices are connected to the display unit, the reference time
required for communication between the display unit and connected
devices (communication cycle time) is stored in LS9400 to LS9527 in
the display unit's LS Area. Values are stored in millisecond
units.
-
The GP3000 series allows the assignment of up
to 4 drivers to one display unit. One driver allows the connection
of up to 32 devices, which varies on the type of connected
device.
For example, when drivers for
Mitsubishi and Omron are added to the display unit, and one
Mitsubishi device and one Omron device are connected, you need to
monitor LS9400 and LS9432.
When a Mitsubishi Ethernet driver is added to the display unit, and
32 devices are connected to the one display unit, you need to
monitor LS9400 through LS9431.
-
The addresses in the LS Area can be viewed by
selecting [Peripheral List] and then [List of Device/PLC Management
Addresses] from the GP-Pro EX [System Settings] window.
5.3.13 System Settings
[Peripheral List] Settings Guide
-
Check the
communication line with a line monitor.
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