Operating instructions

M300USERSGUIDE SEA
SETUP  113
The order of the acquisition events on the tree is the same order in which they will be used for
acquisition.
For the sync type buffers, especially buffer 0, the 1 hz sync buffer, the fastest acquisition events must
be first. This is to avoid sample jitter with sampling time.
Count
The number of buffer to allocate in shared memory for the M300 to use.
When you click on a buffer (number) from the list, the buffer count will show the current value for
the buffer.
If you click on the project name or acquisition event, the buffer count is disabled. The last value
displayed there is shown.
The number of buffers needs to be sufficiently large to ensure that the M300 has enough buffers of
each type to do acquisition, record, broadcast, formulas, displays, ASCII output, etc.
Life,AsynchronousBufferFrequency/SynchronousLife
In the case of synchronous buffers, the buffer frequency is the buffer life, in other words when the
buffer expires. For the 1 second synchronous buffer, the buffer frequency is set for the same value as
the maximum system frequency specified in the System Board entry. The user cannot modify this
field here.
For example, to have a maximum frequency rate of 100 hz, both the buffer frequency and the System
Board frequency should be set at 100.
In the case of asynchronous buffers, the buffer frequency controls the buffer rearm frequency. This
means the buffer rearm frequency controls the maximum possible number of buffers you can get each
second. In the M200 this was usually specified in PARA 3 of the acquisition table for the master
acquisition event.
For imaging type asynchronous acquisition buffers (2D Grey, 2D Mono, CIP, etc), this means the
buffer rearm frequency controls the maximum number of buffers you can get each second. Assuming
the system frequency is 100 hz and the buffer rearm frequency is 25 hz, this would give at most 25
buffers per second.
For other asynchronous acquisition types, such as serial data, this means the buffer rearm frequency
controls the maximum number of buffers you can get per second. If the data rate of the serial data is
10 hz, then you should typically set the buffer rearm frequency to at least twice as much as the
desired data rate. So this would require a 20 hz buffer rearm frequency.
The system frequency set in the board table, sets the maximum acquisition frequency. In the case of
the buffer rearm frequency, the system frequency limits the number of possible buffer rearm
frequencies.