RS-423 is similar to TIA/EIA-232-F, but features a reduced driver output swing and higher data rates.
RS-423 is an electrical standard, specifying driver and receiver requirements only - there is no common pinout for this interface. Unbalanced driver and a balanced receiver defined. The receivers’ requirements are identical to specified in TIA/ EIA-422-B standard. TIA/EIA-423-B is intended to be referenced by complete standards, such as TIA/EIA-530-A. TIA/ EIA-423-B specifies a unidirectional, multidrop (up to ten receivers) interface. Advantages over TIA/EIA-232-F include: multiple receiver operation, faster data rates, and common power supplies (typically ±5V).
| SPECIFICATIONS | RS423 | RS422 |
|---|---|---|
| Mode of Operation | SINGLE - ENDED | DIFFERENTIAL |
| Total Number of Drivers and Receivers on One Line | 1 DRIVER 10 RECVR |
1 DRIVER 10 RECVR |
| Maximum Cable Length | 4000 FT. | 4000 FT. |
| Maximum Data Rate | 100kb/s | 10Mb/s |
| Maximum Driver Output Voltage | +/-6V | -0.25V to +6V |
| Driver Output Signal Level (Loaded Min.) | Loaded | +/-3.6V |
| Driver Output Signal Level (Unloaded Max) | Unloaded | +/-6V |
| Driver Load Impedance (Ohms) | >450 | 100 |
| Max. Driver Current in High Z State | Power On | N/A |
| Max. Driver Current in High Z State | Power Off | +/-100uA |
| Slew Rate (Max.) | Adjustable | N/A |
| Receiver Input Voltage Range | +/-12V | -10V to +10V |
| Receiver Input Sensitivity | +/-200mV | +/-200mV |
| Receiver Input Resistance (Ohms) | 4k min. | 4k min. |