| Sr No. |
Parameter |
RS -232 |
RS – 422 |
RS -485 |
| 1 |
Wiring for communication |
Single-ended |
Differential |
Differential |
| 2 |
Signal type |
Unbalanced |
Balanced |
Balanced |
| 3 |
Output voltage |
|
Logic 0 |
+ 5 to + 15 V w.r.t GND |
+ 2 to – 6 V on terminal A w.r.t B |
+ 2 to + 6 V on terminal A wr.t B |
|
Logic 1 |
-5 to -15 v w.r.t GND |
– 2 to – 6 V on terminal A w.r.t B |
– 2 to – 6 V on terminal A wr.t B |
| 4 |
Data rate |
20 kbps (max) |
100 Mbps at 15 m 100 kpbs at 1200 m |
100 Mbps at 15 m 100 kpbs at 1200 m |
| 5 |
Maximum cable length |
15 m |
1.2 km |
10 km |
| 6 |
Maximum drivers |
1 |
1 |
32 |
| 7 |
Maximum receivers |
1 |
7 |
32 |
| 8 |
Source impedance |
300 Ω |
100 Ω |
100 Ω |
| 9 |
Load impedance |
3 to 7 kΩ |
4 kΩ |
|
| 10 |
Direction |
Uni-direction |
Uni-direction |
Bi-direction |
| 11 |
Communication type |
Full-duplex |
Half-duplex – 2-wire full-duplex -4-wire |
Half-duplex |
| 12 |
Point-to-point/master-slave |
Point-to-point |
Master-slave |
Master-slave |
