Texas Instruments 990 Installation And Operation Manual page 20

~
945423-9701
Table 2-1. Terminal Site Installation Requirements
Requirement
Display Only Keyboard Only
Display /Keyboard
Minimum Width 508mm
508mm
508mm
(20 in.)
(20 in.)
(20 in.)
Minimum Depth
483 mm
216 mm
711 mm
(19 in.)
(8.5 in.)
(28 in.)
Minimum Vertical
345 mm
Free access to
343mm
Clearance
(13.6 in.)
keys (keyboard is
(13.5 in.)
102 mm (4 in.) high)
Recommended Height of
Mounting Surface from
Floor:
Seated Operator
711 t0914mm 711 mm
711 mm
(28 to 36 in.)
(28 in.)
(28 in.)
Standing Operator
1067 to 1270 mm 1067 mm
1067 mm
(42 to 50 in.)
(42 in.)
(42 in.)
Operating Temperatures
O°C to 40°C*
O°C to 40°C*
0° C to 40°C*
(32°F to 104°p)
(32°F to 104°F*)
(32°F to 104°F*)
Operating Humidity
5% to 95% 5% to 95%
5% to 95%
Altitude
3048 metres 3048 metres
3048 metres
(10,000 feet)
(10,000 feet)
(10,000 feet)
*At sea level. Derate to 32°C (90°F) at 3048 metres (10,000 feet).
2.2.1 MOUNTING SURFACE. The VDT components require adequate mounting space on a
flat, horizontal surface. The space must allow room at the rear of the display unit for cable
connections, clearance at the front of the display unit for adequate viewing, and operator access
to the front of the keyboard. The mounting surface must be free of any material that could
block the- ventilation louvers on the underside of the display unit. Consideration of the
operator's normal position (sitting or standing) when using the terminal determines the height of
the mounting surface.
2.2.2 CABLING RESTRICTIONS. Cable lengths affect the positioning of the equipment at the
site. If the keyboard is operated as a separate unit from the display, it must remain within 1.52
metres (5 feet) of the keyboard input connector on the rear of the display due to the length of the
cable. This restriction also ensures that the operator can clearly view the display screen. In addition,
the display unit must be within 1.83 metres (6 feet) of a grounded outlet for input power. The
display can be positioned up to 5 metres (16.4 feet) away from the controlling Model 990
Computer through the use of a single basic cable assembly. Distances in excess of 5 metres (16.4
feet) up to a maximum of 610 metres (2000 feet) from the computer can be achieved through the
use of an optional extension cable assembly. The extension cable assembly (Part Number 946093)
2-2
Digital Systems Division