NIU problems

An NIU can drop off the UTILITY NETWORK at times and these notes will help to resolve this.

NIU's are located at:

  1. Cass
  2. UES
  3. GHRIL
  4. Control room blue cabinet (2 units)

If there is no communications with a particular instrument from ICL, first try a   ?net  command from either the DMS or autoguider window and check that an acknowledgement message is received. If not, re-boot the NIU connected to the appropriate (deaf) instrument by pushing the recessed switch on the back panel.

n.b. The problem may be with the NIU itself. Changing this with a KNOWN working spare is the only solution.

If there is no acknowledgement from SYS or BAK (ie. the MicroVaxes LPVF and LPVG) then you will need to restart the Vax (ucx) software. To re-establish the link, using a telnet session from any machine, login to LPVG (or LPVF) as:

and follow the prompts. Entering  ?net  again should kick the UTILITY network into life!

First issued: 21/6/01 ejm
This file: ~eng/ops/wht/niu_problems.html