Document type:
Title:
Revision date:
Revision:
User's Manual (MUT)
Mod. V1724 8 Channel 14bit - 100MS/s Digitizer
06/11/2007
7
NPO:
Filename:
Number of pages:
Page:
00103/05:V1724x.MUTx/07 V1724_REV7.DOC
63
40
reports the required size, not the actual one, of the event), the Trigger Time Tag, the
Event Counter and the part of the event required on the channel addressed in the Event
Block Request.
After data readout, in order to perform a new random readout, it is necessary a new
Event Block Request, otherwise Bus Error is signalled. In order to empty the buffers, it is
necessary a write access to the Buffer Free
register (see § 4.16): the datum written is the
number of buffers in sequence to be emptied.
Fig. 3.24: Example of random readout
3.12.3. Event
Polling
A read access to Event Size register (see § 4.33) allows “polling” the number of 32 bit
words composing the next event to be read: this permits to perform a properly sized
(according to the Event Size information) BLT readout from the Memory Event Buffer.
3.13. Optical
Link
The board houses a daisy chainable Optical Link able to transfer data at 80 MB/s,
therefore it is possible to connect up to eight V1724 (64 ADC channels) to a single
Optical Link Controller: a standard PC equipped with the PCI card CAEN Mod. A2818.
The A2818 is a 32-bit 33 MHz PCI card; the communication path uses optical fiber cables
as physical transmission line (Mod. AY2705, AY2720, AI2705, AI2720). The Optical Link
allows to perform VME read (Single data transfer and Block transfers) and write (Single
data transfer) operations.
The parameters for read/write accesses via optical link are the same used by VME cycles
(Address Modifier, Base Address, data Width, etc); wrong parameter settings cause Bus
Error.
VME Control Register bit 3 (see § 4.34) allows to enable the module to broadcast an
interrupt request on the Optical Link; an 8 bit mask (see § 3.13.12 and § 3.13.13) allows
to enable the corresponding A2818’s to propagate the interrupt on the PCI bus as a
request from the Optical Link is sensed.
VME and Optical Link accesses take place on independent paths and are handled by
board internal controller, with VME having higher priority; anyway it is better to avoid
accessing the board via VME and Optical Link simoultaneously.
N.B.: Optical Link is not available on the Mod. V1724LC
The following diagram shows how to connect V1724 modules to the Optical Link: