Xycom XVME-560 Manual page 36

XVME-560 Manual
September, 1984
Table 3-6. Examples of -5 to +5 Volt Input Range
Encoded in Offset Binary (a) and Two's Complement (b)
D15
+Full scale 0 0 0 0 1 1 1 1
Zero 0 0 0 0 1 0 0 0
-Full scale 0 0 0 0 0 0 0 0
D15
+Full scale
0 0 0 0 0 1 1 1
Zero 0 0 0 0 0 0 0 0
-Full scale 1 1 1 1 1 0 0 0
3.7
A/D CONVERSION MODES
The AIN may operate in four possible A/D conversion modes. They are:
Random Channel -- a single A/D conversion is performed on any channel.
Single Channel -- repeated A/D conversions are performed on a specified
channel.
Sequential
any specified channel.
External Trigger -- the last channel selected is sampled only when a
positive TRIG signal is received on pin 50 of JK2
The following sections describe these operating modes. The modes are selected by
specifying the proper "mode code" using bits Ml and MO of the control register (see
Section 3.4.1).
Offset Binary
High Byte
0 0 0 0 0 0 0 0 -5V (+1/2 LSB)
Two's Complement
High Byte
1 1 1 1 1 1 1 1 +5V (-1 LSB)
0 0 0 0 0 0 0 0 0 v
0 0 0 0 0 0 0 0
Channel -- channels are sampled in sequence, beginning with
Low Byte
DO
1 1 1 1 1 1 1 1 +5V*4096(-1LSB)
0 0 0 0 0 0 0 0
(a)
Low Byte
DO
-5V(+i/2
(b)
3-9
4095
0 v
LSB)