Yaskawa SmartTrac DeviceNet Card - Manual (Page 29)

SMART TRAC DeviceNet Card
Technical Manual 3554-0070 Troubleshooting Your Smart Trac DeviceNet Card
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Status and Error Message Global Variables
Global Variable (format
is <Card Name>_Variable
Type Source Action
<Card Name>_CAN_OL BOOL CAN Bus
Status
Word, Bit
0 (OL) Set when CAN interface initialized and
ready to communicate.
<Card Name>_CAN_OR WORD CAN
overrun
counter
at offset
003Ch CAN receive queue overrun counter is
incremented when a CAN message is
lost due to a full receive queue.
<Card Name>_CAN_RO BOOL CAN Bus
Status
Word, Bit
6 (RO). Set when messages received from
bus faster than application can
process them. RO indicates an upper
layer application error (in the
application module). Report this
condition to your MagneTek
Application Engineer.
<Card Name>_CAN_RX WORD CAN RX
counter
at offset
0036h CAN receive counter is incremented
when messages are received.
Messages that fail the receive filter still
increment the CAN RX counter.
<Card Name>_CAN_SA BOOL CAN Bus
Status
Word, Bit
15 (SA) SA is set when the scanner is active
<Card Name>_CAN_TA BOOL CAN Bus
Status
Word, Bit
4 (TA). TA set when a pending transmission is
not acknowledged within 25-50ms. TA
indicates that no other nodes are
present (or on-line) on the network
<Card Name>_CAN_TO BOOL CAN Bus
Status
Word, Bit
5 (TO). Set when a pending transmission is
incomplete within 25-50ms. TO
indicates excessive message traffic at
a higher priority than the aborted
message.
<Card Name>_CAN_TX WORD CAN TX
counter
at offset
0032h. The CAN transmit counter is
incremented when messages are
submitted to the CAN controller
Troubleshooting DeviceNet Network
Problems
Use the following general guidelines to troubleshoot your DeviceNet network:
1. Disconnect parts of the network and watch where the fault goes. This
method does not work well for problems such as excessive common
mode voltage, ground loops, electrical interference and signal distortion
because disconnecting part of the network frequently solves the
problem.
2. If the network was previously operating, determine what has changed.
3. Record symptoms in detail. Keep good notes about your network and
its problems to properly define the problem.