Amir Hesam Olfati - Alborz Microsystem Company, Qazvin, IRAN, amirhesam@alborzmicrosystem.com
Amir Maleki Pargou - Imam Khomeini International University, Qazvin, IRAN, amir_maleki30@hotmail.com

SCADA system is a type of telemetric control system in which the remote terminal unit is considered as a telemetric control device in charge of field data acquisition and transmission to controlling centers through telecommunication platforms as well as applying the received commands to the process under supervision.In this paper, standards of digital input apparatus in telemetric control devices are investigated and the dynamic characteristics of signals are studied thereafter. A sample hardware construction for digital inputs is proposed in accordance with electromagnetic compatibility and the effective factors on electromagnetic interference is further discussed. The novelty of this paper is the presentation of an algorithm based on chattering filter which assets noise reduction and input reading stability.

AMS-R3000 RTU, SCADA, Chatterfilter, DI