Yaskawa Microtrac LAN ARCNET Active hub User Manual
Page 15
OPERATION
11
What To Do When the Recon Indicator Lights Up
4/23/97
Proceed as follows for each LAN segment:
1.
Disconnect all nodes from that LAN segment, including the Hub
connection, by removing the TEE from all nodes, taking care that they do not
touch anything.
2.
With an ohmmeter, check cable resistance at the cable end that plugs
into the Hub. This resistance should be 93 ohms from the center pin at the
BNC to the shield. If resistance is greater than 93 ohms, there is an open or
missing terminator on the LAN segment, or a bad cable. If resistance is
between 0 ohms and 93 ohms, the segment has a wrong type of terminator or a
shorted cable.
3.
Plug the LAN cable into any port on the Hub. The Hub should show
no activity on that port, and no RECONs. If the Hub shows activity or
RECONs, not all the nodes have been disconnected from the LAN segment.
4.
Add 1 node at a time to the LAN segment, watching the RECON
indicator LED. If it stays ‘ON’, disconnect that node and move to the next
node. Note that it is normal for the RECON LED to turn on initially when a
node is added; however, it should soon turn off and stay off.
5.
At this point, you should have a stable network with no RECONs. The
node(s) that were disconnected could have the following problems, depending
on whether the system is new, or if it has been operating for some time with no
problems:
New System
• Duplicate Node numbers on Network; none are allowed.
Action:
Check PAC Diagram LAN I.D. numbers.
Check Remote LAN node hardware Node I.D.
switch settings.
• Hardware failure
Action:
Check power supplies.
Make sure system has a good grounding
scheme. Contact MagneTek for Grounding
Practices publication.
Swap suspected bad hardware PCB with a
known good hardware PCB.
Make sure ARCNET coaxial TEE connector
touches no metal objects other than the BNC
connectors.
Make sure ARCNET coaxial termination resistor
touches no metal objects other than the TEE
connector.
RD 90-279
© 1997 MagneTek, Inc.
97-04