P300H P300 Series Modem Installation and Operating Handbook Page 178
Type 1
Low offset voltage, for <100kbps. Defined in this
1985
document for
MIL-STD-188-114A INTERFACE
The P300 Series terrestrial interface is compliant with the interfaces defined in MIL-STD-188-114A when
set in RS422 mode.
This MIL-STD document specifies three types of `balanced generators`
compatibility with
older equipment .
Type 2:
3V offset maximum, for 100kbps to 10Mbps. MIL-STD-188-114A actually
specifies this corresponds to the EIA RS-422A balanced generators
Type 3:
New terminated voltage generator for >10Mbps
Strictly the P300 Series is compliant with the Type 2 interface, defined for use from 100kbps to 10Mbps,
however in the P300 Series this interface will also operate down to 4800bps. The low offset voltage
Type 1 generator is not supported, but as specified for use with older equipment in 1985, should not be
an issue today. The Type 3 is for data rates beyond the P300 Series operating range, and also is not
supported.
A few notes from MIL-STD-188-114A
Connectors, pin assignments and communication protocols are not standardised in this MIL-STD
document
FED-STD-1030A may be considered equivalent to EIA RS423A and CCITT V.10
FED-STD-1020A may be considered equivalent to EIA RS422A and CCITT V.11