Sensor Buses

[Sensor Buses] [Sensors]

Sensor Buses are a subdivision of Industrial "Field Buses". Sensor buses offer few capabilities and are the lowest grade of existing industrial Field Buses.
Sensors require few complex commands and options, while the higher lever Field Buses require more options having more complex operations to perform.
Control Buses reside above the Sensor and Field Buses and require the most complex bus protocol.
A list of different types of physical sensors is listed on the Sensor Manufacturers page:
Acceleration Sensors, Pressure sensors, Hall Effect Sensors, Optical Sensors, Position Sensors, Proximity Sensors, and Temperature Sensors.
Many Sensor Buses use the M12, Circular Industrial Connector.

AS Interface (ASI) Description

ASI: Actuator Sensor Interface. Used to network sensors and actuators. ASi is a two wire interface; Power and Data.
Based around ProfiSafe [developed from Profibus DP].ASI bus was developed by Siemens Automation.
This is a Unshielded 2-wire [Yellow cable], Unterminated, Ungrounded Sensor Bus. The Topology may be either Bus, Ring, Tree, or Star at up to 100 meters.
Power is provided by a 24V floating DC supply, which can supply at least 8 A over the network.
The AS-Interface is an open standard based on IEC 62026-2 and EN 50295.
The AS Interface may also be termed the 'AS-Interface', 'ASI Bus', or 'ASi-Bus'.
Read more about AS-Interface at

BiSS-Interface Description

The BiSS-Interface is a digital interface for sensors and actuators, introduced by iC-Haus as an Open-Source interface in 2002.
BiSS is based on the InterBus standard and is compatible with the Synchronous Serial Interface (SSI).
The BiSS-Interface is operated in either of two configurations [Interface Topologies], Point-to-Point or Chained.
In the point-to-point interface the Master [Controller] connects directly to a Slave [Sensor].
While in a chained configuration the Master only connects to the first and last Slave interfaces in the chain.

The Master outputs the differential clock [MA] to each device.
In the case of driving an actuator the master also outputs a differential data line [MO].
While connected to a sensor the Master accepts a differential data line [LO] from the sensor.
In a chain, the master outputs MO to the slave which receives data as SI and passes data out on SO lines.
The controller [Master] also supplies the voltage and return connections.

The interface uses two unidirectional lines Clock and Data lines at speed up to 10 MHz with TIA422 and 100 MHz with LVDS.

CAN Bus Description

CAN Bus is listed on its own page. CAN bus is used both as a normal field bus, and as a Sensor bus.

Consumer Electronics Bus Description

The CEBus operates over 110V AC powerline [PLC], twisted pair [TP] cable, coax cable, RF and Infrared interfaces.

European Installation Bus [EIB] Description

The EIB bus transmits data up to 9600bit/sec over RS-485, and is used in building and home automation. Additional physical layers include Powerline, RF and infrared.

IEEE 1451 Bus Description

IEEE Standard for a Smart Transducer Interface for Sensors and Actuators-Transducer to Microprocessor Communication Protocols and Transducer Electronic Data Sheet (TEDS) Formats

Industrial Field Bus Description

The main Industrial Field Buses list. A Sensor bus is one of three types of Field Buses.

Interbus-S Bus Description

Interbus-S is a ring-based and may be based on Programmable Logic Controllers [PLC] units.

Intramodule Multielement Microsystem Bus Description

The IM2 bus is part of IEEE 1451.

I2C Bus Description

The I2C Bus may be used as a sensor bus, but was really designed as a battery control interface. The I2C bus has limited range and moderate speed ratings.

InterBus Description

Developed by Phoenix Contact; uses the following standards:DIN 19258, EN 50.254 and EIA-485 for the electrical interface. Based on a Ring network with one Master and many Slaves running at 500kbps [2Mbit/sec max] at full-duplex. A maximum bus length of 400m is allowed between any two slaves, and the total bus length is limited to 13km. Each slave connects to the bus via two full-duplex RS-422 transceivers, one on each side of the slave. So each slave is connected to the follow-on device via an RS422 link. An additional local bus connected to the main remote bus via a bus coupler may also exist, but does not use RS422. The slave may also function as a bus-coupler. Multiple local-bus loops are allowed, local buses use CMOS voltage levels.

Comparing InterBus Buses {}

IS2 Bus Description

The IS-Squared interface may be based off the I2C bus.
The bus has one data/address line and a clock line [200KHz], supporting one bus master and up to 128 nodes.

M-Bus Description

M-Bus, Meter Bus, Used for remote reading of heat-meters and various sensors and actuators.

ModBus Description

Developed by MODICON in 1979. ModBus Protocol is a messaging structure, and does not define a physical layer.
Normally RS232, RS422, or RS485 are used as the physical layer. EIA or TIA may be substituted for RS.

Refer to for standards Info and protocol data.
It appears that ModBus is still active, but it is based on these older serial interfaces.

Generic Buses

Any interface bus may be used as a sensor bus.
These buses in common use may be found operating as a sensor interface RS232, RS422, or RS485.

Serial Peripheral Interface Bus Description

Serial Peripheral Interface Bus [SPI] operates at 10Mbps and can support multiple devices at full-duplex.

Seriplex Bus Description

The Seriplex is widely used in the the automotive sector. The Seriplex interface may be controlled by the Seriplex Technology Organization.
The Seriplex interface may be found on 7000 foot networks accommodating several 1000 interconnect points.

System Management Bus

The System Management Bus, or SMbus is based on the I2C interface.
SMbus may be found on circuit boards as an interface between IC's and on-board sensors.
A temperature sensor interface would be a common example.

Synchronous Serial Interface Bus Description

The Synchronous Serial Interface, or Serial Synchronous Interface [SSI] bus consists of four signals;
SCLK [differential twisted pair], SDATA [differential twisted pair], Power and Ground [twisted].
SDATA is a bidirectional [three-state] data line which requires a pull-up or pull-down resistor.
Data is sent in 8 bit bytes, LSB first. The SCLK signal is only active during transfers.
Data is clocked out on the falling edge and clock in on the rising edge [of the Master].
Two additional signal are also sometimes found; SDEN0, and SDEN1.
The other pins SDEN0 and SDEN1 are active high enable pins and may not be defined in the specification.
The electrical interface is compatible with TIA422 / TIA485 signaling levels.

SSI block diagram between sensor and controller
SSI Interface

The signals are Twisted Pair, with the power line [24 volt DC] being twisted with the ground line.

{Industrial Sensor Bus top}

PC motherboard

Distributor rolodex Electronic Components Electronic Equipment EDA CDROM Software Engineering Standards, BOB card Cabled Computer Bus Electronic Engineering Design Table Conversion DB9-to-DB25.
DistributorsComponents Equipment Software Standards Buses Design Reference

Modified 1/11/12
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