A/D Converter DISOBOX ® Plus

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  • - Local weighing electronics IP66 
  • ƒ – One measuring channel per load cell 
  • ƒ – Can monitor individual load cells 
  • ƒ – Electronic corner adjustment 
  • ƒ – Digital transmission of measured values 
  • ƒ – Fieldbus connection 
  • ƒ – All components can be replaced without requiring or reverification recalibration 
  • ƒ – Can be combined optimally with 
  • - Schenck Process weighing electronics, legal-for-trade PC programs or standard PLCs

 

Application

The Schenck Process DISOBOX Plus is a multi-channel, on-site analogdigital converter unit. The output signal of each load cell connected is digitized separately. This allows the measuring voltage of each individual load cell to be accessed at any time – for many applications an invaluable advantage:

  • ƒ- in commissioning (analysis of dead weight distribution, electronic corner adjustment)
  • - ƒin operation (analysis of the load distribution on the scales, load cell monitoring)
  • - and in case of a fault (rapid identification of the components affected)

The digital transmission through a standard fieldbus system is fast, fail-safe and easy to project. These features make the DISOBOX Plus an ideal data recording and control unit for weighing systems – in combination either with Schenck Process DISOMAT® series weighing terminals, or with PC-based weighing systems or PLC controllers.

Typical applications are:

  • - Road weighbridges
  • - Bin weighers
  • - Security relevant overload control systems as per EN-ISO 13849 However, the integrated scales functions also enable the device to be operated as a multi-channel scale indicator for, for example, a series of simple bin weighers.

Equipment

The DISOBOX Plus has up to 8 measuring channels (model-dependent). One load cell can be connected to each channel. The fact that each individual signal can be accessed individually allows each load point to be calibrated separately (‘electronic corner adjustment’) without requiring the box to be opened, without plugging, soldering, …

Each channel has its own highresolution analog/digital converter (not a multiplexer). This makes the DISOBOX Plus also suitable for measuring and controlling fast sequences – e.g. of feeds. The integrated I/O signals allow direct control of time-critical signals such as an overload shutdown by bypassing the connected control systems. The individual load cell signals can also be accessed separately during operation, in order to e.g. monitor the sensors or, in case of a fault, to localize quickly the source of the fault.

Integrated diagnostics functions in the DISOBOX Plus allow automatic monitoring of the load cell zero-point and the load distribution on the scales. Individual measuring channels can be bundled together to form a maximum of eight independent groups. Each group corresponds to a complete, legal-for-trade scales, with:

  • ƒ – Filtering of the weight values
  • ƒ – Status determination (idle, …)
  • ƒ – Tare memory
  • ƒ – Zeroing
  • ƒ – Multi-range / multi-interval function (3 ranges)
  • ƒ – Zero tracking

 

Communication

All measured values (channel values and scales weights) can be transmitted on to higher-level systems through the serial interface. The optional cards available allow adaptation to all standard industry communication systems. Available at this point in time are:

  • ƒ – PROFIBUS DP-V0, data width 256 Byte, max. data transfer rate 12 MBaud
  • ƒ-  DeviceNet
  • ƒ – The Modbus-RTU protocol can be connected via the internal serial interfaces directly.

ƒ The following protocols are supported by the permanently installed Ethernet interface

  • ƒ – Modbus-TCP
  • ƒ – UDP
  • ƒ – Ethernet IP (optional)
  • ƒ – The Ethernet interface can also be used to configure the device.

Key advantages of communication via Ethernet are the ability to use existing network infrastructures, the high data transfer rate and parallel access of multiple partners to a device (e.g. to make a diagnosis during normal system operation). (External access via internet can of course be restricted as desired or disabled completely by introducing the appropriate privileges).
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The DISOBOX Plus serial interfaces are not reserved for communication with the plant control system. Other peripheral devices can also be connected, such as:

  • - ƒ Serial I/O expansion
  • - Second display or large display
  • - Printer

 

Inputs/Outputs

The DISOBOX Plus inputs and outputs (6 inputs/ 6 outputs, 24 VDC) also allow direct, local process control, in the form of overload messages, feed contacts or release signals.

 

Configuration/Calibration

Used in combination with Schenck Process systems (DISOMAT, PC programs, DISOVIEW E), configuration and calibration are usually performed using the connected master. The configuration program DISOPLAN® is used for comprehensive configurations or if the DISOBOX is used in conjunction with thirdparty systems. It allows access to all parameters for the complete calibration and can indicate weight values if required.

Furthermore, the complete status of a DISOBOX Plus can be read out (backup) and loaded (restore) into a similar device or a replacement if necessary. DISOPLAN runs on the platforms Windows 2000, XP, Vista and Windows 7. It communicates with the DISOBOXes either:

  • ƒ – Point-to-point
  • ƒ – Via an RS485 bus
  • ƒ – Via Ethernet

 

Legal-for-Trade Verification

The DISOBOX Plus has EU certification as a legal-fortrade weighing system, both as an A/D converter in combination with a DISOMAT Tersus or the Schenck Process PC software DISOVIEW E or as a stand-alone scales, for instance in combination with a suitable display and operating console.

The certification allows that in case of a fault the complete active electronics can be replaced without the need for adjustment or a re-calibration – all adjustment and calibration parameters are stored in a non-volatile memory in the passive part of the system. Together with the DISOPLAN backup / restore function, this allows downtimes to be avoided effectively.

The system’s sealing concept, with no jumpers, normally allows it to keep the DISOBOX always closed. Parameterization and adjustments are made through the serial interface, the legal-for-trade protection is performed by a change counter for the relevant parameter. This removes the risk dirt or moisture entering the electronics during maintenance or calibration.

 

Dioview E

Many data-intensive weighing applications, such as road weighbridges or batching systems, today use a PC as a high-performance and comfortable operator guidance – usually in combination with conventional
weighing electronics to implement the legal-for-trade display and the data storage.
The combination of DISOBOX Plus with the legal-fortrade scales program DISOVIEW E opens up a range of new possibilities.

  • - The DISOBOX is located on-site at the scales
  • - Data is transmitted digitally to the PC interference-free
  • - There are no additional devices next to the PC to cause interference
  • - DISOVIEW E displays the legal-for-trade, comfortable and flexible scales directly on the PC monitor
  • -  The DISOVIEW E application interface allows simple access from the operator program to the data and the scales functions

DISOVIEW E can display up to 16 legal-for-trade scales. Please refer to the data sheet BV-D2066 for details on DISOVIEW E.

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Accessories

The DISOBOX Plus is powered by a nominal 24 VDC (permissible range 18 – 36 V). This power will often be available on-site.

However, up to three DISOBOXes can be supplied by the VNT 20410 supplementary power supply unit. The VNT 20410 can also convert a serial RS232 interface (PC COM) to RS485. This allows a DISOBOX to be located at a distance of 300 m away.

There is also a scales simulator to test the hardware and the process flow, the VWZ 21000, with which up to 8 load cells can be simulated individually.

  • ƒ – DISOBOX Plus units with integrated overvoltage protection for the load cell connections as an optional extra are also available.

 

Non-Standard Applications

In addition to the weighing applications already described, the DISOBOX can also provide solutions to tasks that cannot be solved using conventional weighing electronics.

  • - If one does without the individual load cell monitoring option, a group of load cells can be attached to each measuring channel instead (attention must be paid to the overall impedance).
  • ƒ- In this case, a DISOBOX Plus can measure the weight of up to eight scales (e.g. surge hoppers) and transmit the data to a control system.
  • - The fact that each measuring channel can be configured individually means thatthe DISOBOX Plus allows scales to be constructed with load cells of differing rated capacities or sensitivities, e.g. for systems with greatly differing loads at the individual points of support.
  • ƒ- This feature allows, for example, the repair of systems with load cells that are no longer available. Instead of having to completely re-equip the scales with new sensors, now the defective load cell can simply be replaced (any restrictions that may apply due to the permissible combination of load cells used must be considered in legal-for-trade systems).
  • - The DISOBOX Plus is installed in the place of the previous junction box. In many cases even the old measurement cable for serial data transmission can be retained. This can turn a necessary repair into an attractive upgrade.
  • ƒ- Plastic housing:

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  • - Stainless steel housing: 300 x 200 x 121 mm (L x W x H), fastened with 4 clips, hole distance 330 x 144 mm, max. bolt diameter 10 mm
  • - Power supply unit VNT 20410

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Technical Data

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