Mitsubishi QJ71PB92V-U-HW User Manual page 3

[Design Precautions]
When a communication error occurs on PROFIBUS-DP, the status of the
faulty station is as shown below.
Create an interlock circuit in the sequence program using the communication
status information to ensure the system operates safely (Input X1, buffer
memory 5A20
An erroneous output or malfunction may cause accidents.
(1) The QJ71PB92V holds the input data before the communication failure.
(2) When the QJ71PB92V has gone down, the output status of each DP-Slave
is dependent on the QJ71PB92V parameter setting on GX Configurator-
DP.
(3) When a DP-Slave has gone down, the output status of the other DP-
Slaves is dependent on the QJ71PB92V parameter setting on GX
Configurator-DP.
Do not output the "use prohibited" signal as the output signal to an intelligent
function module from the programmable controller CPU.
Writing data into the "system area"or outputting a signal for "use prohibited"
may cause system malfunction in the programmable controller.
When a stop error has occurred to the CPU module, the communication
status varies depending on the error time output mode setting of GX
Developer as shown below.
Set the communication status for when a stop error has occurred to the CPU
module according to the system specifications.
Note that, if the QJ71PB92V is mounted to a redundant system, it operates as
described in (1) regardless of the setting.
(1) When "Error time output mode" is set to "Hold".
(a) Since the communication with the DP-Slave is continued, values at the
time of the CPU module stop error occurrence are held as the output
data sent to the DP-Slave from the QJ71PB92V.
(b) Input data received from DP-Slaves are updated into the buffer memory
of the QJ71PB92V.
(2) When "Error time output mode" is set to "Clear".
(a) Communications with DP-Slaves are interrupted, and output data are
not sent.
(b) Input data received from DP-Slaves are held in the buffer memory of
the QJ71PB92V.
to 5B19 (23072 to 23321)).
H H
DANGER
A-2