Signal transmission in process instrumentation and control systems is largely done via electrical transmission but there are a few areas where pneumatic transmission of signals is vital especially where electrical signals or sparks can ignite combustible materials for example in … Read more
Tag: Signal transmission
Features of Analog Signal Transmission
Analog voltage or current signals are hardwired between the transmitter and the receiver. These analog signals can be relatively be slow to settle compared to digital signals, due time constant of the lead capacitance, inductance and resistance.
Analog signals … Read more
Basic Features of Controller Area Network (CAN)
Controller Area Network (CAN) is a serial communication protocol developed primarily for applications in the automotive industry. It is also capable of offering good performance in other time-critical industrial applications.
The CAN protocol is optimized for short messages and uses … Read more
Topological Network Structures used in Fieldbus Systems
Topology is an important property of fieldbus. It is employed in the selection and definition of the best and suitable physical layout of the fieldbus network. The physical layer of the fieldbus has to meet somewhat demanding requirements like immunity … Read more
Features of HART Communication Protocol
HART is an acronym for (High Addressable Remote Transducer). HART is implemented in two ways in industrial instrumentation networks:
- Point to point system
- Multidrop system
HART Point to Point System
Here serial communication data is superimposed onto a standard 4-20 … Read more
How Signal Processing Circuits are protected from high currents & voltages
How RS-232, RS-422 and RS-485 Networks are applied in Instrumentation
RS-232
Presently, this standard is known as TIA-232C. These are point-to-point networks with a purpose of connecting only two devices. The signaling is single-ended (unbalanced) which implies that the respective voltage pulses are referenced to a common ground conductor and … Read more
Basic Features of Foundation Fieldbus (FF)
Foundation fieldbus (FF) and Profibus are the two most universal serial data bus formats that are used for interfacing between the central processor and smart devices in the process control system.
The Foundation Fieldbus is mainly used in U.S. while … Read more
4-20 mA Transmitters (2-wire, 3-wire and 4-wire Types)
Background of 4-20 mA Signal Transmission
Initially signal transmission was dominated by pneumatics before the advent of 4-20 mA signal standard. The standard was 3-15 psi pneumatic signal where the 3 psi was the ‘live zero’ and 15 psi represented … Read more