Panasonic FP2 - Manual (Page 14)

FP2−CCU Functions of Computer Communication Unit
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1.4 Communication Conditions and Restrictions Relating to Functions
1.4 Communication Conditions and Restrictions
Relating to Functions
1.4.1 Precautions when Using the FP2 CPU Unit −1
If the processing of commands and responses sent from a host computer or display
panel extends over multiple frames, a busy error (error code 53) will be returned to other
ports if communication is currently being carried out on one port, and communication will
be inhibited on those other ports. Combinations to which this restriction applies are
shown in the diagram below.
CPU
B
B B B A
A A A
Power
supply
5 15 3 A M
¦ L
CCU CCU CCU
For example, during the time that a
program is being read at the tool port
of the CPU unit, a communication er-
ror will occur at the display panel
connected to the COM.1 port of the
Computer Communication Unit.
Group A Group comprising the tool port of the CPU unit and the COM.1 port . . . . .
of the Computer Communication Unit
Group B Group comprising the COM. port of the CPU unit and the COM.2 . . . . .
port of the Computer Communication Unit
A similar restriction also applies if access is being made from another station connected
with the link unit.
Unit No. 1 (source station) Unit No. 2 (other station)
When remote programming is being carried out from
another station connected with a Multi−wire Link Unit
(MW), a communication error will occur at the Group A
ports on the source station side.
CPU
B
B B
B
A
A A
A
Power
supply
CCU CCU MW Power
supply
CPU MW