NDACS 8031

General Description

The NDACS 8031 card is an digital opto-isolated input card capable of detecting the status conditions for 32 digital inputs. It is designed for low cost industrial control applications and is used for sensing the status of proximity sensors, micro-switches, level switches etc

Isolation

Each input channel forms a separate opto-isolated circuit. The circuits are isolated from the main chassis and as well as from one another. The maximum differential voltage between the inputs and the chassis is 1000V. The high differential operating voltage allows the cards to be simply installed and operated in many industrial applications without any special installation precautions being required.

The opto-isolators fitted within the 8031 card are selected to enable input signals up to a maximum of 240 V AC/DC to be directly connected to the device., The inputs are protected from excessive high voltage surges by the nature of their high input impedance.

Hot Swap Operations

The 8031 module utilises a hot swap method of systems maintenance. The cards can be simply removed and replaced while the full system is still in operation without fear of causing any physical damage or stopping the data acquisition operations.

High Speed Counters

Channels 0,1, 2 & 3 can be configured as high speed counters allowing digital pulse trains to 100,000 pulse a second to be counted. The counter utilises the rising edge of the digital pulse train to detect a new pulse and to increment the counter.

Digital Counting

For low speed pulse count applications the counting of the digital inputs can be performed as a software operation within the Supervisory software. The maximum count rate would be limited polling time of the software, but generally count rates up to 10 Hz can be performed.

or high speed counting operations up to 10 KHz then 2 high speed counters have been included. The count rate is recorded into status registers that can be read and reset by the supervisory software. The counters can be reset automatically at 1 second intervals or manually by software.

AC Input Operations

• Used for sensing On/Off AC signals
  
• Designed with filtering on the input and a hysteresis amplifier for high noise rejection and transient free switching.
  
• Applications include sensing the presence or absence of voltage, or sensing contact closure from typical sources such as thermostats, proximity, limit, selector push-buttons and toggle switches.

• 12-240V Digital inputs
• Hot Swap Capability
• Digital Read-back
• 1000V Opto-isolation
• Quick Remove Boards
• LED Status Indicators
• 2 x Digital Counter - 100,000 Counts/Sec

The input mode is uni-directional, that is only positive signals will be recorded. The digital inputs can take AC or DC signals. When the soft filtering mode is selected, the sensing time is extended to 20 ms, so that 50 Hz AC signals will be analysed over one period of oscillation.

Using the digital input port to receive analogue signals and the soft filtering option enables the hardware to determine if an AC signal is present. This feature minimises the sample rate to obtain the correct statistical values from an analogue input which in most cases would be require sampling rates faster than the polling rate available within most SCADA packages.

DC Input Operations

• Used for sensing ON/OFF DC Voltages
• Pulse Counting
• Applications include sensing the presence of voltage, or sensing contact closure from typical sources such as TTL compatible devices, proximity, limit and toggle switches.

Systems Latency

When in use with the 8100 processor card and suitable control software on a data server the 8031 card can make a reading and action an event in under 10 mS no matter how many input channels are in use

Digital Input Ranges

The 8034 module can accept a wide range of digital input signals without any requirement for signal conditioning. The input ranges that can be used is:

Low = 0 < 3V
High = 3V to 240V AC/DC

Compliance to European Union Directives

This product is approved for installation within the European Union and EEA regions. It has been designed and tested to meet the following directives: