Honeywell UDC2800 User Manual

CHAPTER
11
MODBUS RTU FUNCTION CODES 20&21
This section describes the function codes needed to upload and
download the configuration from a host computer into the
instrument.
NOTE: The UDC 2800 MODBUS addresses are different with
legacy UDC modules.
Table 11-1: Modbus Function Codes 20&21 Definitions
Function
Code
Name Usage
20 (14h) Read General
Reference
Used to Read or upload the instrument’s configuration
into the host device.
See Function Code 20 (14h) - Read Configuration
Reference Data for more information.
21 (15h) Write General
Reference
Used to Write or download an instrument’s configuration
into the instrument from a host device.
See Function Code 21 (15h) - Write Configuration
Reference Data for more information.
General Information
This instrument uses a subset of the standard Modbus RTU function
codes to provide access to process-related information. Several
MODICON function codes are implemented too. It is appropriate to
define instrument-specific "user-defined" function codes. Where
differences occur between the two protocols it will be noted. Several
standard Modbus RTU function codes are supported, see Standard
Modbus Read, Write and Override Parameters for more information.
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Honeywell UDC2800 Specifications

General

Control Modes	PID, ON/OFF, Manual
Mounting	Panel Mount
Display	Dual 4-digit LED
Input Types	Thermocouple, RTD, mA, mV, V
Output Types	Relay
Power Supply	100-240 VAC, 50/60 Hz
Communication	RS-485 Modbus RTU
Enclosure Rating	NEMA 4X