27
ASYNC 232
↔
422/530 CARD
The Card operates at frequencies of 20 KHz or less and has been per-
formance-tested using twisted-pair cable with the following characteristics:
Wire Gauge
Capacitance
Resistance
19 AWG
83nf/mi or 15.72 pf/ft.
0.0163 ohms/ft.
22 AWG
83nf/mi or 15.72 pf/ft.
0.0326 ohms/ft.
24 AWG
83nf/mi or 15.72 pf/ft.
0.05165 ohms/ft.
The following data rate/distance results were obtained during bench tests
using or simulating cable with the characteristics listed above:
Data Rate (bps)
Gauge (AWG)/Distance (Mi)
19
22
24
38.4—115.2
5.6
3.1
2.5
0—19.2
9.4
5.6
4.4
For optimum performance from your Async 232
↔
422/530 Card, keep the
following guidelines in mind:
•
Always use twisted-pair wire
—this is not an option.
• Use twisted-pair wire with a capacitance of 20 pf/ft. or less.
• Avoid twisted-pair wire thinner than 26 AWG (in other words, avoid
higher AWG numbers than 26).
• Use of twisted pair with a resistance greater than the above specifications
may cause a reduction in maximum distance obtainable. Functionality
should not be affected.
• Many different environmental factors can affect the maximum distances
obtainable at a particular site. Use the data rate/distance table as a
general guideline only.
Appendix A. Cable Recommendations