Toshiba V Series Manual page 150

Chapter 7 Troubleshooting
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(2) Communication with slave devices interrupted
If the 7-segment LED indicates an error code, remove the cause of the trouble,
referring to 6.2 Indications of the 7-Segment LED.
Table 7-2 Slave Device Communication Check Items (2)
DN311 Check S controller power.
Check network cable connections (wrong wiring, breaks). Refer to 3.4
Connection to the Network.
Check the node address settings (for duplicate node addresses).
Refer to 3.2.2 Rotary switches for node address setting.
Check the network communication rate settings (same communication
rate). Refer to 3.2.1 DIP switches for operation mode/communication
rate setting.
Check the local node parameter settings and the scan list. Refer to
4.3.3 Parameter setting request (local node) and 4.3.4 Parameter
setting request (Slave devices).
Slave device Check the slave devices for normal operation, referring to the manual
for the slave devices.
Check thee power unit of the slave devices themselves.
Check network cable connections (wrong wiring, breaks).
Check the node address settings (for duplicate node addresses).
Check the network communication rate settings (same communication
rate).
Check setting items specific to the slave devices.
Network Check the terminators at both ends of trunk cables (121Ω).
Check the maximum network length specified. Refer to 1.2.2 Trunk
line/drop line and maximum cable length.
Check the drop cable length (6 m or less).
Check the total extension of drop cables. Refer to 1.2.2 Trunk line/
drop line and maximum cable length.
Check the network power supply method and power capacity. Refer to
3.5.1 Network power supply method and 3.5.3 Network power unit (24
VDC).
Check the grounding of the network cables. Refer to 3.5.4 Network
grounding.
(3) Overrun errors
CAN controller in the DN311 unable to process the received data as fast as the data
input speed.
The number of overrun errors is stored at 02C5H in the RAS information area. How
to deal with overrun errors:
(1) Lower the network communication rate. (500 kbps → 250 kbps → 125 kbps)
(2) If both types of slave devices, polling and bit strobe, are on the same network,
select polling transmission mode 1 by a local station parameter setting request.
(In this mode, polling response is waited for after polling is requested of each
slave device.)
Description of Check
model 3000 DeviceNet Module Manual (DN311/DN311A)