Category: Eaton

Operation

The FBT-6 is connected to the network using the clip-on probes at the

end of the cable. The red probe is connected to the fieldbus + wire,

the black probe to the – wire and the green probe to the shield wire.

The + and – test leads are polarity sensitive and the Monitor will not

operate if they are reversed.

When first connected to a fieldbus, a version number is displayed

for several seconds. The Monitor then performs an Overall Network

Check to give the user a quick indication of network health.

The “FUNCTION” and “SELECT” buttons are used to select from

network parameters that can be examined with the Monitor. When

a function is selected, the data portion of the LCD display is blank

until the Monitor has collected and processed the data. After that,

the measured value is shown. The indication “OK” is shown if the

measured value is within the acceptable range. The indication “BAD”

is shown if the measured value is outside of the acceptable range.

The rotating symbol in the lower right corner of the display indicates

that there is network activity. A horizontal bar (underscore) under the

rotating symbol indicates that a frame was detected, but could not be

decoded. This is not a maintained function, so if a single “bad” frame

is detected, the underscore will only display for a short time. Periodic

“bad” frames will cause the underscore to blink.

Here follows a more detailed explanation of each of the Monitor’s

functions.

Retransmit

The FBT-6 checks for any device not responding to a LAS pass token

and indicates the address (decimal and hexadecimal) of the last device

that failed to respond to the LAS pass token, together with the number

of missed pass tokens since the function was reset. If more than 250

re-transmissions are detected, the display will read “250+”. Pressing

and holding the “SELECT” key for 2 seconds will reset the re-transmit

count for all devices to zero. Pressing the “SELECT” button for less

than 2 seconds displays the number of detected, missed pass tokens

for each device.

Add–Drop

If a new device is added to the network, the Monitor will display

its address and signal level. If a device does not respond to a Pass

Token frame, the device is considered “dropped” by the FBT-6 and

the Monitor will display the address and last known signal level of the

dropped device.

Shield Short

If a short circuit between the + fieldbus wire and the cable shield

is detected, “(+) TO SHIELD SHORT” is displayed. If the short

is between the – wire and the shield, “(–) TO SHIELD SHORT” is

displayed. If a detected shield short goes away the Monitor indicates

an INTERMITTENT SHIELD SHORT to (+) or (-).

Save Report

Saves the data collected by the Monitor as a report. Up to 8 reports

may be saved from multiple segments and/or multiple locations on

one segment.

Transfer Report

Connect the Monitor to a PC USB port and transfer the saved reports

to Excel files on the PC.

Set Report Names

Customize the names of the reports saved in the Monitor to easily

identify the report source

Set OK/BAD Limits

Change the limits at which Monitor measurements transition from OK

to BAD to establish customized plant standards.

Modern fieldbus commissioning procedures require various bus

parameters to be measured and recorded. Key parameters include bus

voltage, signal level for each device and noise level on each segment

or at every device on each segment and recording the results allows

a baseline of the fieldbus physical layer to be established. The FBT-6

collects  this data, and allows up to eight file sets of data to be saved

for uploading to a PC via a USB port. The data is uploaded as a tab

delimited text file and may then be used to create comprehensive

commissioning and operations reports. Considerable savings can be

achieved by reducing commissioning time and verifying the accuracy

of the data on the segment.

Data collected from periodic network verification testing or

during troubleshooting can be simply transferred to a file for easy

comparison to the segment baseline/history measurements. Data can

be displayed as tables and graphs using commonly  available software

such as Microsoft® Excel.

Hand-held for portability, the FBT-6 is powered by the fieldbus

so that no batteries or external power source is required. It includes

colour- coded test leads and an LCD display.

• Fieldbus powered

• Device add & drop indication

• Shield short indication

• Measures low, fieldbus and high frequency average and peak noise

• Measures signal level for all segment devices

• Assesses network health

• Connects to intrinsically safe fieldbus in Zone 1 and Division 1

hazardous areas

• Connects to non-incendive fieldbus in Zone 2 and Division 2

hazardous areas

• Uploads measurement data to a PC via USB port

The Fieldbus diagnostic monitor, FBT-6. is used to examine the

operation of a live Foundation™ fieldbus H1 network without interfering

with its operation. The Monitor is intended for maintenance personnel to

verify network operation or to troubleshoot an errant network.

The FBT-6 checks for retransmissions from each device on the

segment, providing a key performance indicator of the networks health.

Measurements of bus voltage level, device signal level, and peak and

average noise level. It displays the number of devices present on the

segment and indicates when devices are added or removed from the

network. It also detects the presence of a short between either of the

signal wires and the cable shield.

Certifications and compliances

FCS-MBT Model:

• Ex II 1 G EEx ia IIC T4

• Ex II 3 G Ex nA IIC T4 Gc

• Class I, Division 1. Groups A, B, C and D, (Temp Code T4) Ex ia IIC T4

• IS/I/1/ABCD/T4 Ta=70ºC

• I/0/AEx ia IIC T4 Ta=70ºC

• NI/I/2/ABCD/T4 Ta=70ºC

• I / 2 / IIC / T4 Ta=70ºC

F100 Model:

• Ex II 3 G

• Ex nA IIC T4 Gc

• Class I, Division 2. Groups A, B, C and D (Temp Code T4); Ex nA IIC T4

• NI/I/2/ABCD/T4 Ta=70ºC

• I / 2 / IIC / T4 Ta=70ºC

FCS-MBT-XE Model:

• Ex II 2 G Ex eb mb IIC T4 Gb

• Ex eb mb IIC T4 Gb

Environmental ratings (all models):

• Operating Temperature: –45ºC to +70ºC

Design features

Terminators are clearly marked with a large ‘T’ making them easy to identify

in the field Provides some differential and common-mode (cable shield) over

voltage protection

The ground connection on the filedbus terminators are used to shunt any surge

currents that may get on the cable shield to a local ground in the junction box.

Although the normal practice is to ground the cable shield in the control room,

this additional ground connection will not cause ground loops.

In the event of an overvoltage on the cable shield, a gas discharge tube fires

and shunts this unwanted current to ground

The fieldbus standards require that buses must be terminated at

both ends to prevent signal reflections. Usually one terminator is

provided by the power conditioner in the control room. The MTL range

of fieldbus terminators are ideally suited to provide the Terminator that

is normally in a junction box in the field (along with a Megablock for

interconnecting devices). A large “T” is placed on all terminator labels

for easy identification of the Terminator location.

Additionally the F100 and FCS-MBT(-XE) provides some differential

and common-mode (cable shield) over voltage protection.

The Ground connection on the F100 and FCS-MBT(-XE) are used

to shunt any surge currents that may get on the cable shield to a local

ground in the junction box. Under normal operating conditions, the

cable shield remains DC isolated from this local ground. Although the

normal practice is to ground the cable shield in the control room, this

additional ground connection will not cause ground loops. However, in

the event of an overvoltage on the cable shield, a gas discharge tube

in the F100 or FCS-MBT(-XE) fires and shunts this unwanted current

to ground.

Fieldbus Segment Calculator

The Crouse-Hinds series MTL Fieldbus Segment Calculator is intended to

assist network and planning engineers when designing and implementing

FOUNDATION fieldbus ™ H1 networks.

It models the behaviour of user-selectable power supplies and device couplers

and provides a rapid “Go/No-Go” indication of the electrical characteristics of

the fieldbus network.

All the relevant parameters of the fieldbus segment are easily configurable,

including field device currents, cable lengths, cable cross-section and number

of fieldbus spurs. Power supply, device coupler and host control system types

are easily chosen from pull-down menus, or can be user-defined.

The new 3.03 version merges the earlier, separate tools for Fieldbus Barriers

and Megablock Device Couplers, and covers the following device types:

• 9180 Series FF general purpose power supplies

• 910x-22 Series redundant FISCO power supplies

• 9122-IS Series simplex FISCO power Supplies

• F100 Series simplex general purpose power supplies

• F800 Series redundant power supplies

• Custom (user selectable) power supplies

• F300 Series Megablock device couplers (general purpose applications)

• F300 Series Megablock device couplers (Ex ic spur applications)

• F200-IS Series intrinsically safe Megablock device couplers

• F200-XE Series Zone 1 Megablock device couplers

• FCS-MBx-SG ‘classic’ Megablock device couplers

• 937x-FB Series Fieldbus Barriers

Wire Connections to the Power Hub are made using pluggable screw

terminal connectors. Pluggable connectors allow easy connecting,

disconnecting, and moving of devices for reconfiguration, maintenance,

and troubleshooting. Two securing screws on each connector ensure

it stays in place.

To connect a device, cut and strip the +,  –, and shield (S) wires,

insert them into the terminals, and tighten the screw terminals. Plug

the connector into a Device Port or the Auxiliary Port and tighten the

securing screws.

A typical use for the Power Hub is to configure, precommission,

test, or calibrate Fieldbus devices. In this case, the Fieldbus device

and host device (Emerson 375 or 475. National Instruments Fieldbus

interface, etc.) are connected to the Power Hub. No other components

are required to have a functioning Fieldbus segment.

Fieldbus devices can be connected to the Power Hub with shielded

or unshielded twisted pair fieldbus cable. The controller (host), if

present, is considered to be a device.

The Power Hub provides a minimum of 30mA of power-conditioned

current for each Device Port. If the current needs of a fieldbus segment

exceed the capability of a Device Port, the Auxiliary Port can also be

used to provide additional power-conditioned current.

The Power Hub can supply up to 315mA of power-conditioned

current for all Device Ports and the Auxiliary Port. The Power Hub can

be mounted on a 35mm DIN rail. For applications where AC power is

not available, the Power Hub can also be mounted on a battery pack

(accessory FCS-A11) for fieldbus power in the field.

Current limiting SpurGuard™ protection for each Power Hub

Device Port limits the current draw of an attached cable and device and

protects against short circuits. A short circuit in a spur cable or device

will not take down the entire segment. The remaining devices on the

segment continue to operate normally.

Power conditioner with terminators for fieldbus networks

• Built-in fieldbus power conditioning

• 5 fieldbus device ports

• 30mA current per device

• Up to 315mA total current

• Auxiliary port for expansion

• Complete with AC power supply

• Battery-pack option 5 fieldbus device ports

The Relcom Power Hub (F11) is the next generation of the popular

Power Hub. Ideal for bench-tops, labs, demonstrations and test setups,

the Power Hub is a mini fieldbus segment in a box—just add devices.

The Power Hub is a combined bulk power supply, fieldbus power

conditioner, two built-in terminators, five ports for attaching devices

(Device Ports), and an Auxiliary Port for expansion and connection of

additional devices. It functions as a zero length homerun with spurs

(star topology).

The Power Hub is powered by a plug-in wall transformer with an

input voltage range of 100-240VAC (50-60Hz). Adapters are supplied

with the transformer for four different country power outlets (North

America, Europe, UK, and Australia).