Category: Eaton

Associated System Components

There are many parallels between the loop components that must be assessed for intrinsic safety as well as

functional safety where in both situations the contribution of each part is considered in relation to the whole.

The MTLx54x module is a component in the signal path between safety-related actuators and safety-related

control systems.

The current to pressure converter, valve positioner, or other field device, must be suitable for the process and

have been assessed and verified for use in functional safety applications as well as its certification for hazardous

area mounting.

The safety system PLC shall have a current output with a normal operating range of 4-20mA but capable of

working over the extended range of 3 to 22mA for under- and over-range. Such controllers will normally also

include a readback facility to enable the detection of open or short circuits in the wiring.

The transmission of HART data is not considered as part of the safety function and is excluded from this analysis.

Variant Description

Functionally the MTL4500 and MTL5500 range of modules are the same but differ in the following way:

– the MTL4500 modules are designed for backplane mounted applications- the MTL5500 modules are

designed for DIN rail mounting.

In both models the hazardous area field-wiring connections (terminals 1-2. and 4-5) are made through the

removable blue connectors on the top of the modules, but the safe area and power connections for the MTL454x

modules are made through the connector on the base, while the MTL554x uses the removable grey connectors

on the top and side of the module.

Note that the safe-area connection terminal numbers differ between the backplane and DIN-rail mounting models.

The analogue output models covered by this manual are:

MTL4546 and MTL5546    single channel, open and short cct LFD

MTL4546C, MTL4546Y, and MTL5546Y    single channel, open cct LFD

MTL4549. and MTL5549    dual channel, open and short cct LFD

MTL4549C, MTL4549Y, and MTL5549Y    dual channel, open cct LFD

INTRODUCTION

Application and function

The MTL454x and MTL554x are isolator modules which enable an analogue 4/20mA control signal to be

passed to a device located in a hazardous area from a safe area. The output current available to the hazardous

area is limited to comply with the requirements of the process explosion hazard. The modules are also

designed and assessed according to IEC 61508 for use in safety instrumented systems up to SIL2 when

the required function is to repeat the loop current within ±2%, and the safe state of the output is <3.6mA

(downscale). Higher integrity levels for a SIF can be achieved by using the modules in a voting architecture.

For ‘smart’ valve positioners using the HART protocol the units allow bi-directional communications

superimposed on the 4/20mA signal current.

There are no configuration switches or operator controls to be set on the modules – they perform a fixed

function related to the model selected. The MTLx546 models are single channel while the MTLx549 models

are dual channel, although both channels must not be used in the same safety instrumented function.

These modules are members of the MTL4500 and MTL5500 range of products.

8701-CA-BI Redundant BIM Carrier

For details on the installation and operation of the BIM Carrier, refer to the PAC8000 I/O

– PROFIBUS DP BIM Instruction Manual, INM8507.

Features

 accommodates two Bus Interface Modules

 supports PROFIBUS-DP

 provides dual PROFIBUS network connections

 can be used with DIN rail or panel mounting

Standard and Extended Diagnostics

The PROFIBUS BIM supports Standard and Extended Diagnostics. While the Standard

Diagnostics provide standard PROFIBUS status information, the Extended Diagnostics

provide detailed information relating to the status of the BIM, the health of the modules

and the status of I/O channels. Depending on the I/O module type, events such as high

and low alarm, open circuit and line fault are detected.

Extended Diagnostic messages are generated on detection of any anomalies in I/O

modules. Use of the diagnostic capability requires suitable support in the host application.

For hosts unable to use diagnostic data in the control algorithm, it is possible to map the

diagnostic data into the input dataframe.

Parameterization

The 8507-BI-DP supports parameterization from the PROFIBUS master.

The configuration is created in a PROFIBUS configurator using details provided in

a GSD file. This method is fast and enables a configuration to be built based upon

“logical” modules which represent the physical modules. Modules are added one

at a time to the configuration.

The configuration is passed from the PROFIBUS master to the BIM at the start of

communication. If the system is stopped and re-started, or if the node goes through

a cold start cycle, the configuration file is retransmitted to the BIM.

Standard and Extended Diagnostics

The PROFIBUS BIM supports Standard and Extended Diagnostics. While the Standard

Diagnostics provide standard PROFIBUS status information, the Extended Diagnostics

provide detailed information relating to the status of the BIM, the health of the modules

and the status of I/O channels. Depending on the I/O module type, events such as high

and low alarm, open circuit and line fault are detected.

Extended Diagnostic messages are generated on detection of any anomalies in I/O

modules. Use of the diagnostic capability requires suitable support in the host application.

For hosts unable to use diagnostic data in the control algorithm, it is possible to map the

diagnostic data into the input dataframe.

The 8507-BI-DP Bus Interface Module (BIM) provides the communications

link between the PAC8000 series I/O modules and a PROFIBUS-DP host.

High-speed acquisition of data from the modules and LAN operation speeds

of up to 12 Mbaud allow the host to respond rapidly to changes in process

conditions.

8507-BI-DP Bus Interface Module

For details on the installation and operation of the BIM, refer to the PAC8000 I/O

– PROFIBUS DP BIM Instruction Manual, INM8507.

Features

 support for up to 24 I/O modules

 redundant operation

 extended diagnostics for module and channel status

 PROFIBUS network speeds of up to 12 Mbaud

 non-volatile memory for configuration

 configurable via PROFIBUS host

 HART Pass-through support to monitor/configure HART devices

 Configuration/Reset of IP address

8507-BI-DP BIM and 8701-CA-BI Carrier

PROFIBUS DP Bus Interface Module and Carrier

The 8507-BI-DP Bus Interface Module (BIM) provides the communications

link between the PAC8000 series I/O modules and a PROFIBUS-DP host.

High-speed acquisition of data from the modules and LAN operation speeds

of up to 12 Mbaud allow the host to respond rapidly to changes in process

conditions.

The BIM gathers data from the I/O modules and makes it available to the

host upon request. It is a slave tothe PROFIBUS master. As well as cyclic

data exchange, which is required for reading input and writing output data,

the BIM supports PROFIBUS Extended Diagnostics for status information.

The BIM(s) must be used with an 8701-CA-BI Redundant BIM Carrier, described

on page 4.

Redundant BIMs can be used for critical applications. Each BIM in the redundant

pair operates in parallel, continually checking status to enable the backup BIM to

monitor the health of the primary BIM.

Improving equipment s afety

Better termination

• Top/bottom dual chamber terminals provide a more secure

termination for wires of differing size, minimizing the chance that

a wire could become loose

• Applies to contactors up to 500A and manual motor protectors

(MMPs)/combination style controllers up to 65A

Removable electrical bridge

• Removing electrical bridge ensures starter is off-line

during servicing

• Applies to combination style starters up to 15A

Finger-safe and back-of-hand proof

• Requires no additional shield accessories

• Applies to contactors up to 150A and MMPs up to 65A

Improving equipment performance

Electronic DC coils

• Larger pick-up voltage tolerance and operation range

• Consistent switch-on and switch-off

• Voltage dip ride-through

• Surge suppression included 

Better motor performance and

protection

• Phase loss and phase imbalance protection conserve motor life

and ensure optimum motor performance

Excellent quality performance

• XT has best in class warranty PPM (parts per million) when

compared with similar electrical manufacturers

Improving equipment

usability

Slideable DIN rail adapter

• Allows for easy component replacement without removal

of adjacent components and terminations

• Allows for last minute changes and design flexibility

Visible coil power indication

• Enables easy troubleshooting and testing of contactor operation

• Applies to contactors and combination style starters up to 150A

Overload selectability

• 5:1 ratio current adjustment range, selectable trip class

(5. 10. 20. 30) and selectable reset style as standard, allowing

for greater flexibility using less part numbers

Lowering material costs Small contactors

• Smallest 10 hp contactor on the market

• All XT DC controlled contactors have the same depth as AC

controlled XT contactors

• Reduced panel space can help decrease enclosure size and

costs

Side-by-side mounting

• Low coil consumption allows for side-by-side mounting

• Reversing contactors require no additional width for the

mechanical interlock

• Reduced panel space can help decrease enclosure size and

costs

Combination style starters

• Replaces traditional breaker/fuse block with contactor and overload

• Reduced panel space can help decrease enclosure size and

costs

Electronic coils

• Efficient coil design—185A to 2000A

• XT contactors have low coil consumption, translating to

smaller, less expensive CPTs and power supplies

• Unique control scheme allows for direct control from a PLC or low

consumption command device 

• Can eliminate the need for a large CPT and interposing

relay leading to a reduction in component costs, and smaller

enclosure size and costs