Transmitter Hardware Subassemblies; Figure 4: 266 Modbus ® Multivariable Transmitter Exploded View; Table 1: Transmitter Subassemblies - ABB 266 MODBUS User Manual

Transmitter hardware subassemblies

The 266 transmitter consists of multiple subassemblies (Figure 4). Table 1 explains each subassembly and provides additional
information.
Type 2-2 Blindcover
Subassembly
Certification plate
Blindcover
Windowcover
HMI 6-pin connector
Housing, sensor, and flange
Meter LCD (HMI)
®
MODBUS electronics
module
®
MODBUS terminal block +
surge protection
6 | 266 MODBUS® multivariable transmitter User manual 2105216 Rev. AB
Type 2-2 Windowcover
HMI 6-pin connector
MODBUS
Meter LCD (HMI)
Horizontal flange
without drain
Figure 4: 266 MODBUS

Table 1: Transmitter subassemblies

Description
Provides optional certification information, if purchased
Provides access to the wiring terminations
Provides visual access to the LCD display. Removal of the window cover provides access to the user
interface and the hardware DIP switch settings.
Provides connection between the meter LCD assembly and electronics module
The housing protects the transmitter components from environmental conditions and also provides an
explosion-proof rating for the unit. The housing includes two NPT entry points for field wiring and a nameplate
which states the product ID and the unit serial number. The sensor assembly, which provides the electrical
signal from the transducer to the electronics module, is located in the housing neck. The flange assembly
provides the connection to the process stream and is factory-installed in the lower housing neck. The
housing, sensor, and flange assembly are not field repairable or replaceable.
Provides viewing of parameters and readings
Main electronics board, which provides communication and display interface. The electronics module also
contains the DIP switches, which are used to write-protect the device and restore configuration data.
The terminal block provides field wiring terminations for power, RTD, and RS-485 communications. This
assembly also provides surge protection for the remaining electronics.
Housing, sensor, and flange
(see flange options)
Nameplate
®
Electronics
module
Vertical flange
without drain
®
multivariable transmitter exploded view
2 System description
®
MODBUS Terminal
block + surge protection
Type 2-2 Blindcover
½ inch NPT
Certification plate
Horizontal flange
with drain
Vertical flange
with drain