P300H P300 Series Modem Installation and Operating Handbook Page 175
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`
Type 1 Low offset voltage, for <100kbps. Defined in this 1985 document for compatibility
with “older equipment”.
Type 2: 3 V 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 wil l also operate down to 4800bps. The low offset voltage Type
1 generator is not supported, but as speci fied for us e wi t h “older equipment” in 1985, should not be an issue
today. The Type 3 is for data rates bey ond 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 s t andardised 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