Honeywell UDC2500 - Manual (Page 203)

Modbus Read, Write and Override Parameters plus Exception Codes
4/07 UDC2500 Universal Digital Controller Product Manual 189
10 Modbus Read, Write and Override Parameters
plus Exception Codes
10.1 Overview
Introduction
This section contains information concerning Reading, Writing, and Overriding
parameters in this instrument. There are two types of parameters:
• Data Transfer—These parameters include reading control data, option status, and
reading or changing setpoints.
• Configuration Data—All the configuration data is listed in the order in which it
appears in the controller.
Each type of parameter has the identifying codes listed with it.
What's in this section?
The following topics are covered in this section.
TOPIC See Page
10.1 Overview 189
10.2 Reading Control Data 190
10.3 Read Options Status 191
10.4 Miscellaneous Read Onlys 192
10.5 Setpoints 193
10.6 Using a Computer Setpoint (Overriding Controller Setpoint) 194
10.7 Configuration Parameters 195
10.8 Modbus RTU Exception Codes 218
General Information
Non-volatile Memory Retention
• This controller uses non-volatile memory to store configuration data. These
memories are guaranteed to retain data for a minimum of ten years as long as the data
is not written and erased more than 10,000 times. In order not to exceed this number,
it is strongly recommended that configurations which change rapidly such as
Computer Setpoint use the Override feature which does not affect non-volatile
memory.