Busy and Error in the TAB/GAB System
updated: 06-Jul-05
Index
- Generalities
- L1 Busy
- L1 Error
Generalities
L1BUSY and L1ERROR are communicated to the SCL Hub by the VME/SCL
card. Neither the GAB nor the TABs have a direct connection to the SCL.
L1 Busy Generation
L1Busy is generated by the VME/SCL card. It is asserted under the
following conditions:
| Condition |
Time Asserted |
| currently none |
|
L1 Error Generation
L1ERROR is generated in the TAB/GAB system by BC number mismatches. The
path by which this information is transmitted to the VME/SCL card from
where it is sent to the SCL Hub via the SCLR daughterboard is shown
below.
Error Generation in the TAB
Error Generation in the GAB
An error counter in the GAB is incremented if:
- BC Error
set if any of the BC numbers transmitted from the TABs are
unequal or if any are unequal to the GAB's BC
- AND
- SCL Receiver Sync'ed
the GAB is properly sync'ed to the SCL signals
If this counter reaches a preset value
(maxerror,
downloadable
by VME)
then the GAB_L1_Error signal is asserted on the VME/SCL
cable.
Error Generation in the VME/SCL
L1Error is sent to the SCL Hub by the VME/SCL card under the following
conditions:
- GAB_L1_Error is received on the VME/SCL cable from the
GAB