Installation Position Of Units And Access Time; Restrictions On Configuration Capacity - Panasonic FP7 Series User Manual

Overview

1.3.3 Installation Position of Units and Access Time

 Restrictions on installation position of units
• There is no restriction on the installation position of each unit in FP7 series. However, the
access time to the units installed in the expansion block is longer than that to the units
installed in the base block as shown in the table below, and it affects the scan time.
• When large-volume data access is assumed with a communication system unit, a unit in
which interrupt occurs or user programs, it is recommended to install the target units in the
base block. It enables to decrease the scan time relatively.
 Difference in access time between installation positions of units
Access time
Installation
position
Time per word
Base block
0.47 µs/word
Expansion
block (Short 2.5 µs/word
distance mode)
Expansion
block (Long 4.1 µs/word
distance mode)
(Note 1) The values in the above table indicate each time which the CPU unit accesses the units installed in each
block via bus in the I/O refresh processing or operation processing. The scan time that an operation processing
time and base time are added can be confirmed in the status display dialog blox of the tool software.

1.3.4 Restrictions on Configuration Capacity

 Unit configuration capacity
• If units in which a lot of configuration data are set such as a positioning unit are used in the
expansion block a lot, the configuration capacity may exceed the capacity that the CPU unit
can handle.
• Check the configuration capacity in the I/O map dialog box of the tool software in advance.
• The configuration capacity varies according to the functions and settings used in each unit.
Also, the maximum registration capacity to be assigned depends on the number of installed
expansion units.
1-10
Remarks
Ratio to base
block
Even
The total length of expansion cabels is 9 m or
less.
5.3 times
The LED "SP0" on the expansion master unit
turns on.
The total length of expansion cabels is 10 m
to 30 m.
8.7 times
The LED "SP1" on the expansion master unit
turns on.