General Description

The NDACS 8034 card is a multi-purpose device containing digital relay switches, digital inputs and counters. The 8034 is designed for industrial control applications such as switching low to medium power devices for example small motors, pumps, valves etc. Also for counting digital pulses or status levels on digital inputs.

Simple data tests can be performed within the supervisory software to ensure that the relays are switching correctly and alarm messages can be created to indicate channel failures or irregularities. In the event of a failure of either the fuse or the relay itself then alarm status messages can be sent to the supervisory software.

Relays

The relays used on the 8034 card are Omron type G6B relay single pole change devices with a plug-in type base. The use of plug-in type base devices allows for ease of maintenance. If a relay was to fail due to mechanical wear or by overload then it can be replaced by swapping only that unit..

The replacement can be undertaken in minutes. Each relay forms a separate isolated circuit so high potentials can exist between adjacent channels

Digital Inputs & Counting

Each input can be set to read digital input signals > 3V or to act as a counter for pulse trains to 50K Samples/Sec. Each input is opto-isolated and fused.

Read-Back Operations

The 8034 card contains a digital read-back circuit and is used to read the status

• Relays with bases
• Hot Swap Capability
• Digital Read-back
• 1000V Opto-isolation
• Quick Remove Boards
• LED Status Indicators
• TTL Input - to 25V
• Digital Counter - to 50,000 Counts/Sec

of the relay switching operation. Once a switch operation has been issued by the control system software then a check can be made to ensure it has been carried out. The read-back data is obtained from opto- isolators. The digital inputs are isolated from the back plane and from one another. The integral opto-isolation allows the cards to be simply installed and operated in many industrial applications without any special installation precautions being required. Remote diagnostics can be used to indicate any failed relays

LED Indicator

Each relay has a status LED to indicate its operational position and status. A user can observe at a glance that the hardware is in full working order and the position of each relay. The Status LED changes intensity depending upon if it is closed or open. If an LED is not illuminated then the specified relay has to be changed

Auto-boot Self Check Sequence

Like all other NDACS 8000 series hardware the unit at power-up performs an automatic check of its internal circuits and basic functions

Relay Input Circuit

The drawing below shows the individual relay channel circuit. As shown the relay channels can only be used as switches to complete circuit connections. Fuse protection is PCB mounted and the 8034 has to be removed from the instrument rack in order to complete any relay replacements.

Operations

Any of the inputs can be used as a relay switch, digital input or counter channel. The digital input and counter selection is made by simply removing the relay for the specified channel. Each 8034 card contains a configuration EEPROM which is used to store local configuration parameters. Once activated the card goes through a self test operation to determine if the inputs are operating correctly. If any channel has failed then the status LED indicate directly the location of the fault.

Systems Latency

When in use with the 8100 processor card and suitable control software on a data server the 8034 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

The relays and fuses can be removed very simply and replaced in a matter of minutes. The down time of a card is kept to a minimum and most often these simple repairs ensures that boards do not have to be returned to Keynes for repair or replacement.

Relay Bases

The diagram below shows the physical dimensions of the Omron type G6B relays used on the 8034 board.

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: