Download Motorola MVME172 Technical data

EIA-485/EIA-422 Connections
B
Table B-6. EIA-530 Interface Receiver Characteristics
Value
Minimum Maximum
Parameter
Unit
Differential input voltage
±12
V
Input offset voltage
±12
V
Differential input high threshold voltage
200
mV
Differential input low threshold voltage
–200
mV
Differential input hysteresis
50
mV
Input impedance (without termination resistors)
10
KΩ
EIA-485/EIA-422 Connections
The EIA-485 and EIA-422 standards define a balanced (double-ended)
electrical interface, which is used for transmission of serial binary data,
both synchronous and asynchronous. As used here, they use the same DB25 connector and pin assignments as does EIA-530. EIA-485 is a low cost
differential multidrop driver and receiver standard. The quadruple
differential line drivers and receivers that are used in this module are tristate. They meet the requirements of EIA-485 and EIA-422.
Table A-7 lists the EIA-485/EIA-422 interconnections that are available at
serial port B (SERIAL PORT 2 on the front panel) when the port is
configured via serial interface modules as an EIA-485 port or as an EIA422 DCE or DTE port.
B-8
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