FieldServer FS-8700-80 instruction manual

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McQuay Micro Tech Open Protocol Driver Manual

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1.McQuay Micro Tech Open Protocol Description

This document describes the FieldServer driver used to transfer data between a FieldServer and MicroTech® controllers. Transfers are done using the controller's Data Terminal Communications Protocol. In this document the protocol is referred to as the McQuay Micro Tech Open Protocol.

The McQuay Micro Tech Open Protocol driver allows the FieldServer to transfer data to and from devices over either RS-232 or RS-485 using McQuay Micro Tech Open Protocol. The FieldServer can emulate either a Server or Client.

When emulating a Client, the driver enables the FieldServer to request ‘Everything’ from the McQuay device as well as a number of advanced options which allow specific fields to be read or written and device scaling to be applied.

When emulating a Server, the driver provides an emulation of the byte memory of a device and responds to read and write requests.

The following important points and limitations should be noted before proceeding with this manual.

1.Arising from a feature of the McQuay Micro Tech Open Protocol is the peculiarity, that when a multi- byte value is written to a McQuay device, the write is done one byte at a time (one byte of data can be transferred per poll/response message pair) allowing for the possibility (at least for a short period) that the multi byte value is only partially correct until all the messages have been completed.

2.The vendor equipment is limited to a maximum of 9600 baud. Given that each message packet can only transfer one byte of data and that some data of interest is multi-byte, users of this protocol should expect low data transfer rates.

3.Port expansion is not supported for this driver.

4.A document identified as Ed15050 MicroTech Network Operations contains important information regarding the connection requirements of 3rd party equipment such as the FieldServer to a Microtech network. The document also defines a number of limitations for such connections. The following quotations from this document outline some of this information.

FieldServer Technologies 1991 Tarob Court Milpitas, California 95035 USA Web: www.fieldServer.com Tel: (408) 262 2299 Fax: (408) 262 2269 Toll Free: (888) 509 1970 email: support@fieldServer.com

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Contents Driver Manual FS-8700-80 McQuay Micro Tech Open Protocol Table of Contents Page McQuay Micro Tech Open Protocol Driver Manual Provided by Supplier of 3rd Party Equipment Hardware ConnectionsFieldServer Data Arrays Page Page Timing Parameters Driver Related Map Descriptor ParametersDACHILLER1 Damodes Map Descriptor Example 3 WritePage Page Driver Specific Map Descriptor Parameters DACHILLER1 Passive Chiller1 1024 256 Chiller1emulation2 Page Equipment Type 200CFC 200 Series Centrifugal Chiller McQuay Micro Tech Open Protocol Driver Manual Equipment Type 050RPC Reciprocating Chiller McQuay Micro Tech Open Protocol Driver Manual Page McQuay Micro Tech Open Protocol Driver Manual Equipment Type 001ASC Reciprocating Chiller Equipment Type Self-Contained Units SCUs McQuay Micro Tech Open Protocol Driver Manual Appendix A.4. Direct Addressing Appendix A.3 McQuay Equipment Types recognized by the driverPage DACHILLER1 DACHILLER1 NAK Damcqstats UINT32 Page McQuay Micro Tech Open Protocol Driver Manual Appendix C.2. Negative Acknowledgement NAK Appendix C.3. Node ID problems