Envoy ACP/XF Application Programming Manual
EnvoyACP/XF Application Programming Manual–132179
ix
About This Manual
About This Manual
This manual describes how application processes on a Himalaya S-series server can use 
EnvoyACP/XF to perform bit-synchronous communications. Along with the 
EnvoyACP/XF Configuration Manual, this manual replaces the EnvoyACP/XF Reference 
Manual. This manual describes:
•
The general hardware and software environments within which EnvoyACP/XF 
operates
•
Guardian file-management procedure calls that are specific to EnvoyACP/XF
•
Bit-synchronous line protocols supported by EnvoyACP/XF
Who Should Use This Manual
This manual is intended for application programmers who use EnvoyACP/XF to 
communicate with remote computers and terminals. You should have had some prior 
experience with bit-synchronous communications before reading this manual.
How This Manual is Organized
The following table summarizes the contents of each section in this manual. 
Section or
Appendix Title Contents
1 EnvoyACP/XF and the 
Application Task
Provides an overview of EnvoyACP/XF; describes 
the relationship between EnvoyACP/XF and the user 
application; and describes the ways in which 
EnvoyACP/XF and the application control the 
features of bit-synchronous communications.
2 Asynchronous Balanced 
Mode (ABM) Protocols
Describes particular considerations for user 
applications that use an ABM data-link protocol 
(including HDLC protocol).
3 Normal Response Mode 
(NRM) Protocols
Describes particular considerations for user 
applications that use a NRM data-link protocol 
(including SDLC protocol).
4 System Procedure Call 
Specifics for 
EnvoyACP/XF
Provides information about system procedure-call 
aspects that are specific to EnvoyACP/XF.










