Name

tdl -- test communications between LRIS CCD crate and detector

Usage

tdl M,N

Parameters

M

Indicates which camera to test. Currently the only option is 0 for the red camera electronics.

N

Board index number. Possible values are:

1: Leach controller board in CCD rack
2: Timing board in saddle bag
3: Utility board in saddle bag

Description

The tdl program is a VME task used to check communications between various components along the data path between the LRIS CCD and the CCD crate computer. The program is invoked by typing

tdl M,N

at the VME prompt on the CCD crate compter.

This function sends the tdl command to the specified board DSP along with the parameter 0xffffff. This tests all 24 bits of the data path. The tdl command operates by simply echoing the parameter back down the link after it is recieved on the destination board. If the reply value is not the same as the value sent, the data link is presumed to be at fault.

Usage

Since downstream communications depend on upstream communications, always test in the following order:

tdl 0,1
tdl 0,2
tdl 0,3

Output

Successful completion:

-> tdl 0,2
msg = 0X203 0X54444c 0Xffffff
reply = 0X20002 0Xffffff
reply =        0X20002 0Xffffff
value = 0 = 0x0

Unsuccessful completion:

-> tdl 0,2
msg = 0X203 0X54444c 0Xffffff
vmemsgxchng:  DSP reply timeout.  Check power/hardware.
tdl:  vmemsgxchng() failed.
value = -1007 = 0xfffffc11

Diagnostics

tdl 0,1 Fails: This indicates failure to communicate with the Leach controller board. First, perform a hard reboot by power cycling the rack. If this does not fix the problem, consider swapping in the replacement Leach board.
tdl 0,2 Fails: If tdl 0,1 succeeds, this indicates failure to communicate with the timing board in the saddlebag. First, check power to the saddlebag. Next, power cycle the VME crate and saddlebag. Third, check fibers for obvious breakage. Fourth, perform a signal-loss check on all fibers. Next, re-seat the timing board.
tdl 0,3 Fails: If tdl 0,1 and tdl 0,2 succeed, this indicates failure to communicate with the CCD utility board. First, reboot the saddlebag. If still broken, then re-seat the utility board.

Bugs

This command will not show a problem with a bit being stuck high.

Author

John Cromer, Caltech