Status , Counting, Frequency, Period and Plant Timing Functions
18 Channels per module
4 Channels Support up to 20 khz Counting and Frequency Mesurements
4 channels Support Periodd Measurement
Timing Measurement on all Input Cannel State Changes 1 ms Resolution
Measurements Synchronised with other Networked 933 Modules
Local Storage of Data
The 933 Event Recorder module is designed to accurately record events as they are detected. te module provides 18 fully isolated inputs for event measurement. The intended application is for the monitoring of events such as trips and control reaction in industrial plant so that cause and effect can be studied. The main fuction of the 933 is to record changes of inputs against a real time reference. the events are buffered and available to be read into a host computer without the risk of missing subsequent events in the process. Each 933 as ann independant buffer which can be interrogated as required. Input signals areconditioned. Common problems, such as contact bounce, are handled flexibly so multiple events are not recorded on mechanical contacts. The host communicates with the 933 units using RS485 communicaions ink and a small number of commands are used to configure the unit. The resolution of event recording is 1 ms and synchronisation can be maintained between all 933 recorders in a distributed application. Input state changes can also be counted without effecting the event recorderding function. The current sense or status and counter value of input channels can be returned to the host as required. Frequency measurements can be made on all inputs up to a maximum frequency of 400 Hz and on 4 channels, the maximum frequency can be 20,000 Hz. Cycle period and interval measurements can be made on 4 inputs for improves sesolution on low frequency signals. Connection to plant equipment is acheived with disconnectable screw terminal.
Digital modules support three auxillary digital outputs and a digital input. these can be used in combination to drive a local alarm indicator. An alarm state(0 or 1) can be programmed for each status channel. When Frequency, period or interval measurement modes are programmed a high and low level alarm can be set with a threshold deadband to ensure single transitiond to alarm state. High alarm can only be specified for channel set counting. The digital output level of these two alarm outputs is suitable to drive small externally powered relays using an isolated supply.
. The third output is an isolated relay and can be used to drive an audio alarm. This alarm output can be 'Acknowledged' and cancelled by a contact closure connected to the digital. The output will switch again when any alarm channel error condition occurs.
Note: The two alarm outputs and the acknowledge inputs are not isolated from the RS485 communications port