Theory of Operation
Table 3-2
Serial Communications Standards.
Parameter
RS-232-C
RS-423-A
RS-422-A
RS-485
Operation
Single-ended
Single-ended
Differential
Differential
Number Of
Drivers/Receivers
1/1
1/10
1/10
32/32
Maximum Cable
Length (Ft.)
50
4000
4000
4000
Maximum Data Rate †
(Bits per second)
20K
100K
10M
10M
† The ZT 8809A maximum data rate is limited to 56 Kbaud by the UART
A terminated twisted pair should be used to protect the integrity of the
RS-485 signals. A typical twisted pair has a characteristic impedance
in the range of 100 to 130
Ω
, adequate for data transfer rates of up to
10 MHz. The RS-485 balanced inputs can be terminated by installing
resistors at locations R17 and R19, which are adjacent to connector
J6. The resistors should be 0.25 watt or greater and have a resistance
value equal to the characteristic impedance of the twisted pair.
3-7
Содержание ZT 8809A
Страница 15: ...Tables Table B 9 J5 Pin Assignments B 17 Table B 10 J6 Pin Assignments B 18 Table B 11 J7 Pin Assignments B 19...
Страница 334: ...Jumper Configurations W49 W48 A W47 B A B W37 W66 A W50 B C J7 W67 Figure A 11 W37 W47 50 W66 W67 Jumper Blocks A 34...
Страница 346: ...Jumper Configurations W61 W60 W62 W63 W64 A B A B W65 Figure A 13 W60 W65 Jumper Block A 46...