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iC-MB4

BiSS INTERFACE MASTER

Rev B2, Page 2/40

DESCRIPTION

iC-MB4 is a single-chip BiSS/SSI interface master

controller featuring an 8 bit bus interface to industrial

standard microcontrollers. Alternatively an SPI inter-

face enables serial communication between iC-MB4

and the connected microcontroller. Up to 8 BiSS

slaves can be accessed. The BiSS devices are con-

nected to clock line MA1 and data return line SL1 us-

ing RS422 transceivers (Figure 2). The BiSS devices

can be connected directly in noise-free environments.

A maximum of 8 BiSS slaves is supported, each with

their own configurable data sections covering:

1. Sensor data from 0 to 64 bit

(for measurement data, flags like alarm and

warning, life cycle counter, . . . )

2. Register data with 128 bytes per slave ID

(e.g. for device parameters)

iC-MB4 provides two RAM memory banks for each

slave, enabling parallel access of the microcontroller

while new sensor data is being read in. A 64 byte

memory supports register transfers. Sensor data ac-

quisition is started by a microcontroller command or

via pin GETSENS. Alternatively, iC-MB4 can also read

in new sensor data automatically; the cycle time in

this instance can be set as required. The end of sen-

sor data acquisition and reading is signaled at pin

EOT by a high; if faults occur during transmission pin

NER signals a low. Errors in communication can be

verified by the microcontroller via a status register; a

system error message can also enter this register if

bidirectional message pin NER is kept low by external

intervention. iC-MB4 generates a clock signal for sen-

sor communication using an internal 20 MHz oscillator.

The clock can also be supplied externally. iC-MB4

is based on the BiSS master IP family MB100_X.

controldata

Device 1 (Sensor)

Master

clock/

Last Slave

controldata

ID 1..N-1

ID 0

sensordata/

MA+

MA-

SL-

V-

V+

SL+

MA-

MA+

SLO-

SLO+

Figure 1: Point-to-point connection of iC-MB4 to

one device with several slaves

controldata

actuatordata

ID N

ID N+1..M-1

Last Slave

ID 0

ID 1..N-1

Device 2 (Sensor/Actuator)

Device 1 (Sensor/Actuator)

Master

clock/

controldata

sensordata/

MA-

MA+

V-

V+

SLI+

SLI-

MA+

MA-

SL+

SL-

SL-

SL+

MO+

MO-

MAO-

MAO+

SLO+

SLO-

SLR-

MO-

MO+

V-

V+

MA+

MA-

SL+

SL-

SLR+

Figure 2: Example network of iC-MB4 and two devices

The device offered here is a multifunctional iC that contains integrated BiSS C interface components. The BiSS C process is protected

by patent DE 10310622 B4 owned by iC-Haus GmbH. Users benefit from the open BiSS C protocol with a free license which is

necessary when using the BiSS C protocol in conjunction with this iC.

Download the license at www.biss-interface.com/BUA