Honeywell RS-232, Reference Manual

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iv RS232 Communications Reference Manual 8/99
Contents
1. UMC800-RS232 COMMUNICATIONS...................................................................1
1.1 Overview.........................................................................................................................................1
2. RS232 PORT PROTOCOL DESCRIPTION...........................................................3
2.1 Overview.........................................................................................................................................3
2.2 Definition of Error Types ...............................................................................................................3
2.3 DLE Insertion and Deletion ............................................................................................................3
2.4 CRC.................................................................................................................................................4
2.5 Sequence Numbering ......................................................................................................................4
2.6 Response to Link and Physical Errors ............................................................................................4
2.7 Reserved Addresses ........................................................................................................................4
2.8 Static and Dynamic Parameters ......................................................................................................4
2.9 Anatomy of a Message Packet ........................................................................................................5
2.10 Message Exchange Examples .........................................................................................................6
2.10.1 Read Contiguous 32-bit Values..............................................................................................6
2.10.2 Read Scattered 32-bit Values .................................................................................................8
2.10.3 Write Scattered 32-bit Values ..............................................................................................10
2.11 Application Error Codes ...............................................................................................................12
2.12 Sequence of Operations ................................................................................................................13
3. PC COMMUNICATION DRIVER FOR RS232 PORT ..........................................15
3.1 Overview.......................................................................................................................................15
3.2 For the Programmer - Getting Started Quickly.............................................................................16
3.2.1 How Do I Use This Driver?...................................................................................................16
3.2.2 Code sample 1: instantiation of a driver object on the stack.................................................17
3.2.3 Code sample 2: dynamic instantiation of one of two driver objects on the heap..................18
3.2.4 Code sample 3: error handling...............................................................................................19
3.2.5 Multiple Instances of the Driver in the Same App ................................................................20
3.2.6 Port Lockout ..........................................................................................................................20
3.2.7 Managing Multiple Threads ..................................................................................................21
3.3 Taxonomy of Classes....................................................................................................................21
3.4 API Functions Common To All Drivers .......................................................................................21
3.5 Anatomy of a Standard Return Value...........................................................................................22
3.6 Frequently Asked Questions .........................................................................................................23
4. APPLICATION LAYER MESSAGE FORMATS ...................................................27
4.1 Overview.......................................................................................................................................27