Control function of BIS M-4008-048-0xx-ST4
The compact processor unit is the link between data carrier and host system. It manages two-way data transfer between data carrier and compact processor and provides buffer storage.
The compact processor unit writes data from the controlling system to the data carrier or reads the data from the data carrier and makes it available to the controlling system.
Controlling systems may be the following:
– A PLC
Double bit string:
To ensure complete transmission of all data in the data buffer, the control bits in the data buffer's first and last byte (bit header) are transmitted and compared. If both bit headers are the same, then the data is updated completely and can be taken over. This means that the data for each R/W head is only valid if both bit headers are the same. Thus, the host system also must compare the bits in the bit strings.