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VMIVME-3126A High Resolution, Isolated Analog-to-Digital Converter Board
Modes of Operation
The VMIVME-3126A High Resolution, Isolated Analog-to-Digital Converter board
operates in several different modes. Each mode is enabled by the user through the
Board Control Register (BCR). The operating modes are described below.
Normal Mode
The board enters the
Normal Mode
after completing the power-on self-test routines. In
this mode, each input is scanned, digitized, and stored in user-accessible RAM. When
the onboard DSP is not processing data, it is reading the BCR to see if the user has
changed operating modes.
Calibration Mode
The board enters the
Calibration Mode
when the
INIT CAL
bit in the BCR is set by the
user. Entering this mode causes the board to stop processing data and await further
input from the user. If jumper E10 is omitted, the front panel LED is illuminated for a
visual indication of the change in modes from
Normal Mode
to
Calibration Mode
. The
front panel field connections must be removed for calibration. During the calibration
process, VMEbus access should be limited to reading and writing to the BRR, and
writing to the TCVH and TCVL registers. The BRR’s data appears as
$3B00
(
$3B01
for
8-channel option) while calibration is active. Prior to setting the
INIT CAL
bit, the user
Table 1-1
Control and Status Registers
Register
Mnemonic
Description
Board ID Register
BIR
Contains code identifying the board as a
VMIVME-3126A
Board Ready Register
BRR
Status indicating when the board can be
accessed for read/write operations
Board Control Register
BCR
Control functions for board operation
Select Channel Register
SCR
User-select of channels for calibration or
reconfiguration
Pass/Fail Status Register
PFS
Status of channels following self-test
Target Calibration Voltage Register High
TCVH
Upper 16-bits of calibration value - entered by
the user for calibration
Target Calibration Voltage Register Low
TCVL
Lower 16-bits of calibration value - entered by
the user for calibration
Firmware Revision Register
FRR
Contains current revision level of DSP code
EEPROM Writes Register
EWR
Contains the number of times the EEPROM has
been written
Channel Control Status Register
CSR
Provides control of range, data format, input
format, and filter cut-off frequency for each
channel
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