Lake Shore 372, Руководство пользователя, Страница: 78 / 214

66 c
HAPTER
3: Installation
Model 372 AC Resistance Bridge ands Temperature Controller
3.6.6 Scanner Control
Connector Definition A 15-pin D-sub-miniature plug provides power supply and digital control input con-
nections to the 3726 and 3708 scanners. The scanner control cable included with the
scanner is adequate for most installations. A connector pin definition is provided in
case a cable must be made for a special application. Both instrument and scanner
have the same pin numbering, but the instrument has a connector receptacle and the
scanner has a connector plug.
3.6.7 Scanner Control
Cabling A scanner control cable is included with the 3726 and 3708 scanners. Commercial
15-pin extension cables should not be used because the shield is tied to the body of
the connector that is at chassis ground on the instrument. Longer cables can be con-
structed with shield tied to the scanner analog common. The cable must have one
connector plug end to mate with the instrument, and one connector receptacle end
to mate with the scanner.
FIGURE 3-12 Scan control
Pin Name Description
1 Scan present Signal to Model 370 that a scanner is installed
2 Digital common
Common or ground for digital control signals
3 Digital common
4 Unused —
5 Analog common
Common or ground for analog signals 6 Analog common
7 Analog common
8 -15 V -15 V referenced to scanner analog common
9 Scan 1 Scan channel select line 1
10 Scan 2 Scan channel select line 2
11 Scan 3 Scan channel select line 3
12 Scan 4 Scan channel select line 4
13 Scan gain Selects scanner gain of 1 or 100
14 +5 V +5 V referenced to scanner digital common
15 +15 V +15 V referenced to scanner analog common
Body Chassis (Do not use)
Both scanner analog and scanner digital common are tied to isolated measurement circuits
inside the instrument and must remain isolated from the instrument chassis and earth ground.
The connector body should not be used for shielding the scan control cable because the chassis of
the instrument is at earth ground, and the chassis of the scanner is at isolated measurement
common.
TABLE 3-5 Scanner to scan control connector