1 timestamp generator, 2 board reset, 2 hardware configuration – Sensoray 826 User Manual
Page 8: Timestamp generator, Board reset, Hardware configuration
2.1.1 Timestamp Generator
A timestamp generator is shared by the analog input system and counter channels. The timestamp generator is a free-
running 32-bit counter that increments every microsecond. The generator starts at zero counts upon board reset and
overflows every 2
32
microseconds (approximately 71.6 minutes). The timestamp counter is not writable, but the current
timestamp counts can be read by calling the S826_TimestampRead function.
2.1.2 Board Reset
Upon power-up, or in response to a hardware reset, all interfaces and outputs are forced to default initial states. The initial
conditions of the interfaces are discussed in the interface chapters.
2.2 Hardware Configuration
Up to sixteen model 826 boards can coexist in a single host computer. When more than one board is used in a system, each
board must be configured before installation; this is done by setting quad dip switch SW1 to assign a unique identifier
(board number) in the range 0 to 15 to the board.
By default, all model 826 boards are factory configured as board number 0. No reconfiguration is necessary if there is only
one 826 board in the host computer; simply leave it configured at its default board number.
If more than one 826 board will be plugged into a common backplane, the boards must be configured so that each board has
a unique board number. Board numbers are typically contiguous, though this is not required. For example, board numbers 0
and 3 could be assigned in a two-board system, though it would be more common to assign board numbers 0 and 1. This
table shows the relationship between board number and switch settings:
Board Number
SW1-4
SW1-3
SW1-2
SW1-1
Notes
0
OFF
OFF
OFF
OFF
Factory default
1
OFF
OFF
OFF
ON
2
OFF
OFF
ON
OFF
3
OFF
OFF
ON
ON
4
OFF
ON
OFF
OFF
5
OFF
ON
OFF
ON
6
OFF
ON
ON
OFF
7
OFF
ON
ON
ON
8
ON
OFF
OFF
OFF
9
ON
OFF
OFF
ON
10
ON
OFF
ON
OFF
11
ON
OFF
ON
ON
12
ON
ON
OFF
OFF
13
ON
ON
OFF
ON
14
ON
ON
ON
OFF
15
ON
ON
ON
ON
826 Instruction Manual
3
Introduction