These options are each available as a separate purchase to enhance the functionality of the Mi.30, 31 and 40 series board. Please contact Dataquest Solutions for pricing information.
| Synchronisation | Synchronisation by star hub | Synchronous digital inputs | Multiple recording | Gated sampling | Time stamp | Extra I/O |
This option allows connection of up to 4 boards to generate a multi-channel system. It is also possible to build up synchronously mixed mode systems to record analogue channels and digital channels together. Boards of the same type may be connected with each other. It is also possible to connect Spectrum boards of different types where the sync-bus operates in the same, (for example all boards of the MI series).
On the internal sync-bus clock, trigger information is exchanged between the boards. All connected boards use the same clock and trigger. One board is defined to be the master board and therefore generates clock signals for all boards.
When using this kind of synchronisation there is a fixed phase delay between adjacent boards of 500 pico seconds. Another alternative without having this phase delay is the star hub. It allows connection of up to 16 boards of the MI series .
The Star Hub is an additional module for all MI boards. It allows synchronisation up to 16 boards with no phase delay between them. With this option, multi-channel acquisition systems of up to 128 channels are possible, as well as a combination of input and output boards, or analogue and digital boards.
Across the star hub, clock and trigger information are exchanged between the boards. All connected boards use the same clock and trigger. One board is defined to be the master board and generates clock. This master board or another board may be used to generate the trigger for all connected boards.
Download Star Hub information [PDF Data sheet]
With this option free upper bits on the analogue converter are used to store synchronous digital data. On the 12/14 bit boards the upper 4/2 bits may be used to store additional digital data, the 12/14 bit analogue value being hardware expanded to 16 bit for direct storage and use by software. Depending on the board type there is a delay between analogue and digital data capture, however this is fixed to -12 samples for the MI30xx series, -4 for the MI31xx and -6 for the Mi.40xx
Connection to these synchonised digitals is by arrangement shown here. The grey IDC connectors plug onto to the rear portion of the boards PCB, the signals carrried along ribbon cables from 40 pole FX2 Hirose connector(s) on a PC mounting plate. It is for this reason that an extra PC slot width is required.
The option Multiple Recording allows the recording of several trigger events without having to restart the hardware. Events which repeat at a very high rate could be recorded with this option. a recording dead time immediately after each trigger event will occur in this mode, but typically only a few samples in length.
The memory of the board will be divided into several segments of the same size. Each segment will be filled with data when a trigger event occurs. Pre-trigger is not available when using Multiple Recording.
When using boards of the MI.xxxx series Multiple Recording could be combined with the Time stamp option to record the start time of a segment.
The option Gated Sampling allows recording
of a signal controlled by an external gate signal. Data is only
recorded if the external gate signal is equal to a programmed
level (TTL HIGH or TTL LOW).
As an option on some boards, the start and end sample of a gate interval may be marked in memory by combining with the Time stamp option to record start and end of a gate interval.
The time stamp function allows recording of
trigger moments relative to the start of recording or
synchronised to an external radio clock. The time stamp function
is designed as an enhancement to the Multiple Recording and the
Gated Sampling mode but could also be used without any of these options.
The memory of the time stamp function is a FIFO buffer and this
allows continuous signal recording with time stamps. Each time stamp is
defined by samples and therefore the rate of the AD converter clock. The relationship
between trigger events and the count are set by the modes as described below.
Standard Mode
In standard mode the time stamp counter is set to zero once, with a call to TS_RESET. After this call the counter counts continuously. The time stamp of all recorded trigger events are referenced on this common zero time. With this mode the exact time difference between different recordings may be calculated.
StartReset Mode
In this mode the time stamp counter is set to zero on starting the board to record. The time stamps of one recording are referenced to the start. This mode is useful for Multiple Recording and Gated Sampling.
RefClock Mode
The counter is controlled by the seconds signal of an external radio clock. Therefore the counter is divided in a HIGH and a LOW part. The HIGH part counts the seconds that elapse since reset of the counter. The LOW part is resets every second, and defines the position of the trigger event within the current second. The timing signal of the radio clock must be fed into the time stamp module as a TTL signal. For more details of synchronisation please contact Dataquest Solutions. This mode allows the absolute time of a trigger event to be recorded, thus synchronisation of data recorded at different locations.
Download time stamp information [PDF Data sheet]
The extra I/O module offers 24 additional digital I/O and 4 additional analogue outputs to all boards of the MI series. The signals are available from an extra connector which is mounted into the neighbouring PCI slot access plate. All additional lines are independent of the MI board and may be asynchronously set at any time. There is an internal version of this option with 16 digital i/o only and requires no extra slot space. These signals are available from an optional internal flat ribbon connector
Application examples:
Download extra I/O data sheet. [PDF data sheet]
© Spectrum GmbH 20.01.2003
Modified by Dataquest Solutions 11.07.2003