System Guide
TransCore Proprietary
6–2
Chapter 6 Communications Protocols
This chapter describes the communications protocols for the
Multiprotocol Reader Extreme (MPRX).
Introduction
The MPRX supports the following communications protocols:
•
Basic
•
Error correcting
•
Data inquiry
The following protocol information provides reference information relevant to developing
host software.
Communications are performed using the 7-bit ASCII code with optional parity, thus
providing easy setup, testing, and diagnostics with standard ASCII terminals and serial
printers.
Each message is framed within the start-of-message (som) and end-of-message (eom)
characters so that the host device can detect the beginning and end of each message.
This convention is most important under marginal communications conditions during which
the host may receive extraneous noise-induced characters between reader transmissions.
In such instances, the host is capable of ignoring any messages that do not conform to the
som...eom frame sequence.
Both data mode and command mode require a two-way message interchange when using
error correcting protocol (ECP). This interchange is completed by the message recipient
returning a message acknowledgment to the message sender.
With ECP, all transmissions require a message. If a message is not received, the sender will
time out with the same effect as if it had received a negative acknowledgment (from the
host) or an
Error
message from the MPRX.
Software (XON/XOFF) flow control is optionally supported. Be careful in the use of XON/
XOFF since noise-induced characters may be interpreted by the MPRX as the XOFF
character, which would suspend reader output without information reaching the host
device. For more information, refer to
“Software Flow Control” on page 8–16
.
Note: TransCore recommends that XON/XOFF flow control be disabled while using ECP.
Содержание MPRX
Страница 19: ...Chapter 1 Introduction...
Страница 23: ...MPRX TransCore Proprietary 1 5...
Страница 24: ...Chapter 2 Developing the Site Plan...
Страница 37: ...Choosing Installing and Removing Tags Chapter 3...
Страница 48: ...Installing the MPRX Chapter 4...
Страница 64: ...MPRX TransCore Proprietary 4 17...
Страница 65: ...General Software Information 5...
Страница 70: ...System Guide TransCore Proprietary 5 6...
Страница 71: ...Communication Protocols Chapter 6...
Страница 87: ...MPRX TransCore Proprietary 6 17...
Страница 88: ...Chapter 7 Commands...
Страница 127: ...Chapter 8 Configuring the MPRX...
Страница 146: ...Chapter 9 Troubleshooting and Maintenance...
Страница 152: ...System Guide TransCore Proprietary 9 6...
Страница 153: ...Chapter 10 Interface to Train Recording Unit...
Страница 158: ...Chapter 11 Check Tag to MPRX Assembly...
Страница 164: ...MPRX TransCore Proprietary 11 7...
Страница 165: ...Appendix A Glossary...
Страница 171: ...MPRX TransCore Proprietary A 7...
Страница 172: ...Technical Specifications Appendix B...
Страница 175: ...Wiring Diagram C...
Страница 179: ...Command Quick Reference Appendix D...
Страница 203: ...MPRX TransCore Proprietary D 25...
Страница 204: ...Compatible Tag Information E...
Страница 208: ...MPRX TransCore Proprietary E 5...