GEMARK* VIE CONTROL PRODUCT DESCRIPTION

• Automatic reconfiguration

• Accuracy is specified over full operating temperature

• Internal temperature sensor

• LEDs:

- Power status and attention

- Ethernet link-connected and 

communication-active

- Application-specific

• 28 V dc power

• Internal solid-state circuit breaker and soft start

A power supply provides a regulated 28 V dc power feed to each I/O pack. 

The negative side of the 28 V dc is grounded through the I/O pack metal 

enclosure and its mounting base. The positive side has solid-state circuit 

protection built into the I/O pack with a nominal 2 A trip point. Online repair 

is possible by removing the 28 V dc connector, replacing the I/O pack, and 

re-inserting the power connector. I/O packs are automatically reconfigured 

if the Auto-Reconfiguration feature is enabled.

TERMINAL BLOCKS

Signal flow begins with a sensor connected to a terminal block on an I/O 

module. The terminal board mounts to the cabinet and is available in two 

basic types: T-type and S-type modules.

T-type modules typically fan the inputs to three separate I/O packs. 

They contain two removable 24-point, barrier-type terminal blocks. Each 

point can accept two 3.0 mm2 (#12,AWG) wires with 300 V insulation per 

point and spade or ring-type lugs. Captive clamps are also provided for 

terminating bare wires. Screw spacing is 9.53 mm (0.375 in) minimum, 

center-to-center. T-type modules are normally surface mounted, but may 

also be DIN-rail mounted.

A shield strip is provided next to each block, which is actually the left-hand 

side of the metal base where the module is mounted. Wide and narrow 

modules are arranged in vertical columns of high and low-level wiring that 

can be accessed from top and/or bottom cable entrances. An example of a 

wide module is a module containing magnetic relays with fused circuits for 

solenoid drivers.

Box-type and Barrier-type Terminal Blocks in Simplex and Triple Redundant Configuration

S-type modules provide a single set of screws for each I/O point and allows 

a single I/O pack to condition and digitize the signal. This board is used 

for simplex, dual, and dedicated triple modular redundant (TMR) inputs by 

using one, two, or three boards. They are half the size of T-type modules 

and are DIN-rail or surface mounted. Two versions of the S-type modules 

are available: fixed terminal blocks and removable terminal blocks.

Fixed box-type terminal blocks accept one 3.0 mm2 (#12 AWG) wire or two 

2.0 mm2 (#14 AWG) wires with 300 V insulation per point. Screw spacing is 

5.08 mm (0.2 in) minimum, center-to-center. Removable box terminals may 

be replaced with spring-cage-clamp, insulation displacement, or crimpand-stab terminals. A shield strip is provided on each terminal block and is 

tied to functional ground.

TEMPERATURE RATINGS

Mark VIe electronics are packaged in different locations world-wide and 

customized for a variety of protection classifications with and without 

ventilation and cooling. Controllers, I/O modules, power supplies, etc. are 

rated for -30 to 65°C (-22 to 149°F) at the electronics. To compliment the 

Mark VIe Control’s native I/O modules, a variety of fieldbus solutions are 

available with master communication gateways on the I/O network. These 

modules have slightly reduced operating temperature ratings:

• PROFIBUS® Master Gateway: -20 to 55°C (-4 to 131°F)

• CANopen® Master Gateway: -20 to 55°C (-4 to 131°F)

• FOUNDATION Fieldbus™ Linking Device: 0 to 55°C (32 to 131°F)

Modules with reduced operating temperatures should be mounted lower 

in the cabinet to avoid the natural temperature gradient from the bottom 

to the top of the enclosure. Control room equipment such as operator 

stations has an operating temperature range of 20 to 30°C (68 to 86°F). 

For shipping and storage, the controllers, I/O modules, power supplies, etc. 

are rated -40 to 85°C (-40 to 185°F), and control room equipment is rated 

0 to 30°C (32 to 86°F).

I/O MODULES

I/O modules can be categorized as generic and application-specific. 

As an example, discrete inputs (contact inputs) are used in virtually all 

applications and differ primarily in their voltage rating. Other considerations 

in selecting a module are its redundancy, isolation (group or point), terminal 

block type, availability for safety applications (IEC 61508), and approval for 

hazardous locations.

A typical application-specific module is a servo module that is used for 

fast closed-loop control of a turbine’s servo valve actuator or a complete 

emergency over-speed trip system for a turbine. These unique modules 

will not be described in the following tables. However, some applicationspecific modules such as a vibration module is commonly applied in 

monitoring radial and axial shaft displacement of rotating machinery in 

plant distributed control systems and will be described in a separate table.

Analog Input (AI) and Analog Output (AO) Modules

• V/I designates a voltage / current input