Honeywell Digital Input, 24VDC (16 channel)900G02-0202
Terminal Blocks (900TEK-xxxx, 900TBK-xxxx, 900TER-xxxx, 900TBR-xxxx)ControlEdge HC900 I/O modules use terminal blocks with
various features available.
Terminals are available in Barrier style and Euro style.
The Barrier style terminal block provides a floating
washer to accommodate two different size conductors.
The Euro style offers a more compact terminal design
providing more room within the terminal block cavity for
conductors.
All terminal blocks support customer wiring entering the
block from the top or bottom when mounted in the
controller. A locking swing out door provides easy access
for wiring and covers potential high voltage connections
during operation.
For low voltage terminals accepting thermocouple inputs,
cold junction compensation is provided by the AI
modules.
Terminal blocks are secured to the rack assembly with
screws. These screws provide vibration immune terminal
connections during operation and also serve as jacking
screws when removing modules to minimize the
extraction force required.
The rear of the Terminal block provides keying to prevent
accidental terminal block insertion into incorrect module
slots. Labels are provided to identify the module type by
name and color, offer wiring instructions and provide an
area for customer identification of field circuits. Shorting
combs are available for use with Barrier terminal blocks
to connect common signal pairs together or to jumper
together common signals on AC and Relay output
modules.
Shield terminal strips are also available to terminate the
shields of shielded cables at the controller.

Number of
terminals
20 36*
Type Terminal blocks removable
under instrument power.
(Field power disconnected)
Terminal blocks removable
under instrument power.
(Field power disconnected)
Gauge Wires Barrier and Euro: #14 to 26
AWG, solid or stranded
Euro: #12 to 26 AWG, solid
or stranded
Terminal color High voltage: Red
Low Voltage: Black
Black
Contacts High Voltage: Tin Coated
Low Voltage: Gold Plated
Gold plated
Contact Style Post and socket Post and socket
Door Access Tool accessible Tool accessible
Cold Junction
compensation for
thermocouples
Yes (provided by AI
module)
N/A—thermocouples not
used
*Required with the following I/O modules: 16 HL AI, 8 AO, 16 AO, 32 DI, 32
DO and 16 AC/DC DI.
I/O Scanner Module (900S50x-xxxx)
The I/O Scanner 1 module resides in a remote I/O rack
along with the I/O modules. The Scanner 1 and the
controller are connected to each other’s I/O port (see the
photo on the right side of this page). The scanner collects
data from the Input modules populated in its remote rack
and communicates the information to the controller.
Output data is sent from the controller to the Scanner 1
module which in turn sends the data to appropriate output
module. Data exchanges are synchronous with the
controller scan time to maintain deterministic operation.
Diagnostic status of I/O modules is also monitored and
reported to the controller when detected. The Rack
address of a Scanner 1 is set via DIP switches on the
Scanner 1’s circuit board. Connection to the controller
uses IEEE 802.4 Ethernet 100base-TxPhysical Layer. An
external Ethernet switch is required when multiple I/O
scanners are used with a single controller. Scanner 1
modules do support removal and insertion under power.
Number of
terminals
20 36*
Type Terminal blocks removable
under instrument power.
(Field power disconnected)
Terminal blocks removable
under instrument power.
(Field power disconnected)
Gauge Wires Barrier and Euro: #14 to 26
AWG, solid or stranded
Euro: #12 to 26 AWG, solid
or stranded
Terminal color High voltage: Red
Low Voltage: Black
Black
Contacts High Voltage: Tin Coated
Low Voltage: Gold Plated
Gold plated
Contact Style Post and socket Post and socket
Door Access Tool accessible Tool accessible
Cold Junction
compensation for
thermocouples
Yes (provided by AI
module)
N/A—thermocouples not
used
*Required with the following I/O modules: 16 HL AI, 8 AO, 16 AO, 32 DI, 32
DO and 16 AC/DC DI.
Type I/O Scanner
Status indicators Scanner: Module status Red/Green LED indicates mode
or error
Expansion I/O port: Green and Yellow LEDs indicate
receive/transmit
Power supply loading 5V; 770 mA max