Bobson2000
Junior Member level 2
Hello.
I need to design circut between microcontroller and RJ45 connector which should contain PPS (Pulse Per Second), and ToD (Time of Day) signal outputs. I found defined pinout for PPS and ToD in ITU-T G.703, and voltage levels in T-REC-V.11 (recalled in G.703), but just for PPS signal. Based on these documents both signals are differential without isolation, and ground connection between two devices is needed. My device is something like time server, so i made some research, and i found that most this type devices uses DB9 connector for ToD with RS-232 interface - becasue they base on NMEA 0183 ToD format, but NMEA 0183 shows that depending on version v1/v2 RS232, or RS422 is used, when if RS422 is used connecting ground between devices is not recommended (conception conflict). Some of them have configurable RS-422/RS232 socket. Finally i can't find which electrical interface is defaulty used to ToD and PPS in this type devices - meabe somebody know? I can't found information about common used voltage levels/interfaces, example circuit, or some market device schematic, i found just one thread on some forum, but his autor desnt receive any answer. PPS is simplier, but in ToD i thinked about two transceivers RS-232, and RS-485 and switching singnals between transceivers and connectors, or use some voltage and single-ended to differential translator, example DS8922 and utilize just RS422, and differential PPS inputs, or outputs, or meabe i should use Ethernet transceiver with MagJack connector. Im little confused.
Best regards
[EDITED] Now i found that it depends on which standard is used for ToD, and can be used for PPS:
- TIA/EIA uses RS-232, or RS-422/RS485 (different voltage levels)
- ITU-T V.11 uses RS-422
- suggested connectors are DB9, DB25, RJ-45
I need to design circut between microcontroller and RJ45 connector which should contain PPS (Pulse Per Second), and ToD (Time of Day) signal outputs. I found defined pinout for PPS and ToD in ITU-T G.703, and voltage levels in T-REC-V.11 (recalled in G.703), but just for PPS signal. Based on these documents both signals are differential without isolation, and ground connection between two devices is needed. My device is something like time server, so i made some research, and i found that most this type devices uses DB9 connector for ToD with RS-232 interface - becasue they base on NMEA 0183 ToD format, but NMEA 0183 shows that depending on version v1/v2 RS232, or RS422 is used, when if RS422 is used connecting ground between devices is not recommended (conception conflict). Some of them have configurable RS-422/RS232 socket. Finally i can't find which electrical interface is defaulty used to ToD and PPS in this type devices - meabe somebody know? I can't found information about common used voltage levels/interfaces, example circuit, or some market device schematic, i found just one thread on some forum, but his autor desnt receive any answer. PPS is simplier, but in ToD i thinked about two transceivers RS-232, and RS-485 and switching singnals between transceivers and connectors, or use some voltage and single-ended to differential translator, example DS8922 and utilize just RS422, and differential PPS inputs, or outputs, or meabe i should use Ethernet transceiver with MagJack connector. Im little confused.
Best regards
[EDITED] Now i found that it depends on which standard is used for ToD, and can be used for PPS:
- TIA/EIA uses RS-232, or RS-422/RS485 (different voltage levels)
- ITU-T V.11 uses RS-422
- suggested connectors are DB9, DB25, RJ-45
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