Additional Communications Documentation; Using The T200H/M With A Hessen Protocol Network - Teledyne T200H User Manual

Teledyne API - Model T200H/T200M Operation Manual

4.15.3. ADDITIONAL COMMUNICATIONS DOCUMENTATION

Interface / Tool
APICOM
Multi-drop
DAS Manual
* These documents can be downloaded at http://www.teledyne-api.com/manuals/

4.15.4. USING THE T200H/M WITH A HESSEN PROTOCOL NETWORK

4.15.4.1. General Overview of Hessen Protocol
07270D DCN7141
Table 4-33: Serial Interface Documents
Document Title
APICOM User Manual
RS-232 Multi-drop Documentation
Detailed description of the DAS.
The Hessen protocol is a multidrop protocol, in which several remote instruments are
connected via a common communications channel to a host computer. The remote
instruments are regarded as slaves of the host computer. The remote instruments are
unaware that they are connected to a multidrop bus and never initiate messages. They
only respond to commands from the host computer and only when they receive a
command containing their own unique ID number.
The Hessen protocol is designed to accomplish two things: to obtain the status of remote
instruments, including the concentrations of all the gases measured; and to place remote
instruments into zero or span calibration or measure mode. API's implementation
supports both of these principal features.
The Hessen protocol is not well defined, therefore while API's application is completely
compatible with the protocol itself, it may be different from implementations by other
companies.
The following subsections describe the basics for setting up your instrument to operate
over a Hessen Protocol network. For more detailed information as well as a list of host
computer commands and examples of command and response message syntax,
download the Manual Addendum for Hessen Protocol from the Teledyne API' web site:
http://www.teledyne-api.com/manuals/index.asp .
Operating Instructions
Part Number Available Online*
039450000 YES
021790000 YES
028370000 YES
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