1 Introduction

The AMS library enables communications to be opened between ADAM tasks, and commands and acknowledgements to be sent and received. Provided suitable ADAM network (ADAMNET) processes are loaded, communications can also take place across networks. In the absence of ADAMNET processes, communication is restricted to ADAM tasks on a single machine.

The example (see Section A) shows that communicating programs do not have to be strictly ADAM tasks but the term ‘task’ is used throughout this document to mean either end of a communications link. More details on the way ADAM uses AMS can be found in SSN/77

AMS is currently implemented using the Message System Primitives (MSP) and the ADAM Timer (ATIMER) libraries. AMS, MSP and ATIMER are all written in C and included in the Parameter and Communication Subsystems PCS Starlink Software Item. Fortran interfaces (FAMS and FATIMER) are also provided for AMS and ATIMER respectively.

This document describes AMS and its current implementation, keeping the two separate as far as possible in order to clarify the distinction whilst giving readers a feel for the way the whole system currently works.