Mitsubishi Electric AJ71C24-S6 User Manual page 68

4. SETTINGS AND PROCEDURES BEFORE OPERATION
MELSEC-A
(1) Main channel
The main channel in the above table refers to the interface t o which the
computer is connected. The main channel setting is valid only for modes
(
9
to D.
In other modes, the setting switch may be in the ON or OFF position.
(Section 4.5.4 gives the setting examples for different system configura-
tions.)
Setting the main channel defines data flow as shown below:
Data received through the main channel is automatically transmitted
through the sub channel.
Data received through the sub channel is automatically transmitted
through the main channel.
When the mode switch is set to " 9 to "DM, only the processing request
commands, transmitted from other stations and received through the
main channel of the self, are valid with the set mode.
TheAJ71C24 executes the requested processing and transmits the result
through the main channel.
PCCPU AJ71C24 PCCPU PJ7lC24
RS-232C is set to the main channel
RS-422
is set to the main channel
(2)
Transmission specifications
The RS-232C and RS-422 use the same transmission specifications.
They cannot operate with two different transmission specifications set-
tings.
Do not set the "unusable" baud rate setting (SW13, 14, and 15 ON).
If these switches are set, the RUN indicator
LED
(LED No. 0) is turned
OFF and operation is not possible.
(3)
Sum check
Set whether the sum check code is added or not added to the end of the
message, when the computer link operates with the dedicated protocol.
Sections 8.4.1 to 8.4.4 and 8.4.5 (7) give the message structure and sum
check code when the sum check setting is "Enabled".