If I order a basic instrument with no modules how many inputs and outputs do I have

The standard hardware build has 1 Universal PV input and 1 High level analogue input. It also has 7 digital IO that can be configured as input or outputs, 1 digital input and a changeover (form C) relay. Communications for the 2000IO expander is also included. The IO expander terminals can be used for a further digital input with the addition of an external resistor if the IO expander is not being used.

Why do I need a different microboard for Profibus communications

Extra components need to be fitted on microboard for Profibus. We do not fit these as standard because this would increase the standard price.

Do I need a different microboard for DeviceNet

No all DeviceNet circuitry is contained within the DeviceNet module.

How do I interface to the fixed logic I/O

Please refer to TN137 and TN154.

How many thermocouples can I connect direct without external transmitters

Total is five, also applies to RTD, mV and Volts and High Impedance Volts. Inputs are Standard PV, PV Input module(Slots 3 & 6) and AM Input module(Slots 1,3,4, & 6)

Can I connect two analogue signals into the DP module.

Yes you can. One low level signal(TC,RTD,mV) and one high level(Volts, High Z Volts). However be careful these inputs are not isolated from each other.

How many mA inputs can I connect direct to 26/2704

Total is eight, Standard PV Input, Standard Analogue Input, AM modules in slots 1 & 4 and DP modules in slots 3 & 6. Be aware not all inputs are isolated

Why can I only fit the PV or DP input modules into Slots 3 & 6

These modules are very high precision inputs that require some circuitry not on the module. This circuitry is only available at these positions

Why can I not fit an AM module in slot 5

The CJC sensor on the module PCB interferes with the rear terminal connectors

What Isolation barriers exist in the instrument

Standard digital IO and High Level analogue input are not isolated from the 0V rail and therefore not isolated from each other, but are isolated from the mains supply. Standard PV input is fully isolated with reinforced insulation. All modules are fully isolated, however some channels within modules are not. Thermocouples and other sensors connected to the 26/2704 can be at common mode mains potential.

Why can we not use slot 2 for an IO module

If an IO module is fitted in slot 2 the internal instrument will become too hot. Slot 2 will be used for a memory module that will generate minimum heat.

What is included in Standard Toolkit Level

8 Digital Operations, 4 Timers, 4 Totalisers, 3 Custom Lin Blocks, 3 Transducer Scaling blocks, Real Time Clock, Monitor Block, Switchover block.

What is included in Toolkit Level 1

16 Digital Operations, 16 Analogue calculations, 4 User Values, Pattern Generator, Digital(Pulse) Programmer, Analogue Switch blocks 4 Timers, 4 Totalisers, 3 Custom Lin Blocks, 3 Transducer Scaling blocks, Real Time Clock, Monitor Block, Switchover block.

What is included in Toolkit Level 2

32 Digital Operations, 24 Analogue calculations, 12 User Values, Pattern Generator, Digital(Pulse) Programmer, Analogue Switch blocks 4 Timers, 4 Totalisers, 3 Custom Lin Blocks, 3 Transducer Scaling blocks, Real Time Clock, Monitor Block, Switchover block

What is a Pattern Generator

It allows groups of digital values to be selected from a single input source. This source may be provided from the Programmer User Values, from a BCD Input or from a user defined source. An example of its application would be to allow fixed output patterns to be applied in different segments of a program. This is particularly useful where the same pattern is repeated in different segments or in other programs.

What is a Digital Programmer

It provides timed control of a single digital output. It may be used during any segment of a setpoint program or used independently. A sequence of eight Off and On times may be set for the output. A digital programmer is used to pulse digital output sequences thereby reducing the number of segments required in the main program. It is particularly useful in enabling a setpoint program to switch on a vibration table within an environmental test chamber.

What is an Analogue Switch

Provides the user with the facility to select an analogue value based on an input source. For example a program user value could select one of 8 analogue values for retransmission to a slave controller.

What is a Custom Input download

The controller can store up to three custom input linearisations and any PV input can use these linearisations to characterise a specialised input sensor. These linearisations are created by Eurotherm using a software tool that can convert input data in an electronic form to a file that can be downloaded to a controller. It is important to note that this feature should not be confused with the Custom Linearisation Blocks.

What is a Custom Linearisation Block

They can be used to characterise any signal within the controller. They can be applied to inputs and outputs. For example as an input they can condition the input mV signal to suit a special sensor chracteristic, or as an output they can be applied to the normal linear PID output signal to provide a non-linear response.

What is a Monitor Block

It can be used to calculate the minimum or maximum value of any parameter since a reset command. It can also be used to measure the time a value has been above a threshold setpoint.

What is a Switchover Block

It is used to smooth the transition between two input sensors. For instance thermocouple to pyrometer, where the thermocouple is used for signals less than 1100^oC and the pyrometer above.

What is a Transducer Scaling Block

They are used to provide user calibration facilities. For example in Load Cell, Calibration Baths and Melt Pressure applications.

What is User Text

It is a pool of 50 sixteen character text labels that can be used to customise the operator display to suit the process. User Text can be used to provide appropriate names for loops, parameters, alarm messages etc.

How do I connect a vacuum gauge

Active vacuum gauges can only be connected to the 2704. An active gauge contains transmitter electronics in the head that provide an output in the region of 0-10Vdc. The signals can be fed into the standard PV input, PV Input module and AM module. Vacuum inputs are mostly non-linear, therefore the custom download tables are used to convert the input voltage to the desired measurement. Vacuum is displayed in scientific notation

What is a Program User Value

It is a number that can be set in each program segment between 0 and 100. This number can then be wired to other points in a controller configuration. Typically they are used to select in a program segment which pattern generator is active. Program User Values can be custom enumerated so that the operator display will show a different Text Label every time the value is changed.

How many PID sets does the controller have

The main loops have a maximum of 6 and the auxiliary a maximum of 3. In addition to PID values the sets also contain Cutbacks, Power Limits and a configurable Analogue Value.

What can the Analogue Value in the PID gain scheduling be used for

It is a value that is used to be connected to any wireable parameter that needs to be changed at the same time as the PID sets. A typical use is automatic alteration of Feedforward Trim Limits in a cascade

Can a 2604 clone file be downloaded into a 2704.

Yes because the Modbus address map is identical. Some parameters that exist in a 2704 are not present in the 2604 therefore some errors may occur. These can be ignored although the User Interface may require some customisation due to the differing display types.

Can a 2704 clone file be downloaded into a 2604.

Yes because the Modbus address map is identical. Some parameters that exist in a 2704 are not present in the 2604 therefore some errors may occur. These can be ignored although the User Interface may require some customisation due to the differing display types.

I have an old version of firmware. Can I upgrade my controller to the latest version

Yes it can be upgraded by using a firmware upgrade program. The firmware is held in Flash Memory and an upgrade tool is available. All versions of 26/2704 lower that V5.xx can be upgraded to V5.xx.

How do I add Toolkits blocks or other software features if my controller does not already have them.

Extra control loops, programmer, applications and toolkit blocks are all software features that are normally specified at the time of order. However it is possible by using the iTools secure feature to upgrade controllers following delivery. The iTools secure feature is normally restricted to Eurotherm and inventory stocking distributors. It is important to note that software upgrades do require an order number before processing and that an invoice will be raised to cover the order. For this reason it is necessary to register with Eurotherm in Worthing to be authorised to use this facility.

What is the Track IP function

It is a function that allows an analogue input to directly set the control loop output. It is normally used in process control applications to enable operators to start up a process or machine under "manual" operation, for example from a control panel potentiometer. It is worth noting that this start up mode can also be obtained by soft wiring to the Manual OP parameter, but doing it that way prevents the manual OP from being adjusted from the controller front panel in the normal way.

What is a Custom Enumeration

Provides the user with the facility to enumerate parameters with their own text. For example when a digital input=1 the user interface shows "Door Open" and when=0 it shows "Door closed". They greatly increase the operators' ease of use and understanding of what is going on in the process.

How do I use the DP module with a Carbon Probe

First, it must be enabled for dual mode operation. The thermocouple is connected as normal, negative=D and positive=C. Channel C is configured for the appropriate thermocouple type. The probe mV is connected positive=D and negative=A, and the input range should be set for High Z Volts with 0V(Elec High)=0000mV(Eng High) and -1.4V(Elec Low)=1400mV(Eng Low). This connection is required because the TC and mV are not isolated from each other. Connecting in this way cancels out measurement errors caused by earth loops. The linearised values can now be soft wired to the zirconia block.

I have a Sensor Break Alarm, how can I tell which sensor is bad

Scroll to the appropriate input location, either Standard IO or Module IO and check the input status. An open input will show 'SBREAK'. Alternatively in your configuration you can software this signal to a User Alarm which can then display a message

In what order should I install my output boards in the unit, or does it matter

The I/O boards can be installed in any order, because the 26/2704's use wireable addresses. The I/O is not hard-wired to any particular function. You are, however, limited to which location selected boards will function, such as: PV and DP boards to slots 3 and 6. AM boards to slots 1,3,4 and 6.

How do you wire to a value that does not have a 'wireable source'

At this time you can only wire to a parameter which has a wireable address

What is an EDS File

An EDS (Electronic Data Sheet) file is used in conjunction with DeviceNet instruments. It is a simple file format that includes the device's configurable parameters and public interfaces to those parameters. EDS files can be used by network tools to read or set device parameters.

What is a GSD File

A GSD(Gerätestammdaten) file contains information, relating to the instruments parameters, which a Profibus master needs in order to communicate with its slave device. The GSD file for a 26/2704 is created using our GSD file editor.

Can individual programmer segments be altered in 2704 User Pages

No, we do not have enough Modbus addresses in the controller to store for every parameter of each program. Only parameters with Modbus addresses can be promoted to User Pages. However, you can promote and alter the current segment information.

How do I wire more than 1 alarm to the same output channel

Use a logic operator with the OR function. 8 logic operators are included as standard in every controller

Can I configure a control output to you into manual and revert to 0% power when the mains supply is switched on.

Yes, there is a parameter found in the Loop Set-Up in versions V4.xx(2604) and V5.xx(2704) called "Start up Mode".

How many Master Comms parameters do I have in the 26/2704

38 in 2704 and 25 in 2604. All are available as read or write. Note we plan to extend the 2704 to more parameters in the future

What can I communicate to with Master Comms

In theory any Modbus slave, including PLC's. Certainly as far as Eurotherm instruments are concerned series 2000, 2500, 900EPC, 902,818,808 and so on.

What is the configurable modbus address map

It is a function block(only available as a special) that allows a customer to redirect communication requests from an address identified in a master to an equivalent parameter at a different address in the 26/2704. This is particularly useful when customers want to replace older Eurotherm controllers with the 26/2704 and do not want to alter their supervisory software.

Why can the Dual DC output not provide 0-10V or 0-20mA

The main reason is that the existing circuit topologies could not resolve the conflict of requirements between power drive capability (set by industrial standard for 4-20mA current loops) and the maximum power dissipation limit imposed by the size and material of the 26/2704 casing. In other words, even if we managed to squeeze 6 channels of standard output design capable of providing the minimum power to drive the loop then temperature inside the instrument would exceed that of its melting point. Consequently, a new design approach had to be adopted that ensured that the output module is capable of diving various loop impedance's with high power efficiently. Offering only 4-20mA range ensured that we strike the best compromise of all the other factors such as material and production costs and available space for the module

How do I get high precision retransmission

Use an HR module in retransmission feedback mode. Refer to TIBC160

What is retransmission feedback mode

It is a retransmission technique that feeds the actual retransmission back into a control loop as a PV. The target retransmission is the setpoint and hence the PID control loop automatically compensates for both temperature and time drifts. This technique utilises the low noise HR module. For detailed information refer to TIBC160

How do I calibrate a VP feedback potentiometer

When using VP bounded mode you need to switch on the Cal Enable parameter. When this parameter is on you are allowed to move the motor up and down by pressing the raise and lower keys. You can then follow the normal calibration procedure for a potentiometer input module. For more information refer to TIBC157

Can I connect two melt pressure sensors to a 26/2704

Yes, assuming that you have sufficient space to fit all the modules

What transducer calibration facilities do I have in the 26/2704

Shunt(melt pressure), load cell and comparison calibration. Auto tare is also a feature. The 26/2704 has three transducer scaling blocks

What vacuum sensors do the 2704 support

Only active type gauges providing high level analogue outputs. The full list in detailed in the iTools/Linearisations/vacuum folder

How do I connect to unsupported vacuum sensors

If the gauge is an active type(0-10Vdc output) then we will need either a transfer formula usually found in the gauges operator manual or a table of pressure versus vacuum. Send this information to Cameron Large at Worthing who will arrange for the linearisation curves to be created.

What is the Oxygen Exponent in the zirconia list

It is a scalar for the oxygen PV. It is required because the oxygen PV in an incinerator will be about 6%, but in a heat treatment furnace the PV is likely to be shown in PPM in the range 100 -1000. 100 PPM is equal to 0.01 %O2

How do I get my oxygen PV in PPM

Set the oxygen exponent to 4

Does the 26/2704 support EI-Bysnc communications

Yes, but we only support a subset of parameters the total number being in excess of 100. Included are most of the common parameters such as Loop PV,SP,OP etc. Setpoint program download using bisync is not possible because the fundamental structure of the 26/2704 is different than the 900EPC and other instruments