The ADLP-80 was developed by ASEA (ABB) for communication between a SCADA system and RTUs.
Its physical layer uses a specific PCM encoding type consisting of a 4-bit
start code and one or more 14 or 19-bit words.
ADLP-80 operates in half-duplex mode following the master/slave principle.
A master can communicate with up to 15 RTUs, an RTU only responds to an explicit
request from the master.
ADLP-80 Application Layer
PCM RS232 (V.24)
Supported Information Types
Setpoint BCD [3 decades]
Single indication [1 Bit]
Double indication [2 bit]
Single indication [1 Bit] with time tag
Double indication [2 bit] with time tag
Measured value [11 bit]
Counter value [12 bit]
proprietary PCM encoding, half-duplex
on-demand transmission of digital, analog and counter values on-demand transmission of digital and analog values on change transmission of digital indications with time tag (events recording message) Direct transmission of commands and setpoints "Select before operate" transmission of commands and setpoints Clock synchronization
RTU addresses 1..15 up to 59 groups with up to 16 digitals each up to 31 groups with up to 8 analogs each