Mitsubishi Electric A1SJ71DN91 User Manual page 41

3. SPECIFICATIONS
(6) Master Communication Status (Address 01B0
The master communication status is shown by the upper and lower bytes, as shown
below.
(a) Upper Byte
This byte shows the DN91 I/O communication status. It contains a value indicating
the communication status, as shown in Table 3.15.
Value
0000 OFFLINE
H
0040 STOP
H
0080 CLEAR
H
00C0 OPERATE
H
When powering ON, after normal completion of self-diagnosis and parameter check,
the state automatically advances from "OFFLINE" to "OPERATE".
When Refreshing (Xn1) is ON, "0" data is sent to reset the output data of slave
stations.
While setting parameters, the state advances from "OPERATE", "CLEAR", "STOP",
and to "OFFLINE".
OFFLINE
STOP
CLEAR
OPERATE
(b) Lower Byte
This byte shows the device network communication status. The bits turn ON/OFF
according to the communication status, as shown in the diagram below.
Bit 7 Bit 6 Bit 5
Always OFF
The bit turns ON when the
corresponding problem occurs.
/432)
H
Table 3.15 I/O Communication Statuses
Name
Initializing
I/O communication stopped
Resetting output data for all slave stations after 0 data
was sent.
Conducting I/O communication
Bit 4 Bit 3 Bit 2 Bit 1
−
3 19
MELSEC-A
Operation
Bit 0
Abnormal communication
with a station
Since communication with
a slave station failed, out-
put to all slave stations has
been turned OFF.
Parameter error
Severe network problems.
Communication cannot
continue.