112 • I/O modules
Counter modules 750-404/000-003
Modular I/O System
ETHERNET TCP/IP
Structure of CONTROL and STATUS byte
The control byte has the following bits:
Bit 7 Bit 6 Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
0
T
VD
REQ
Output
value at
output O2
Output
value at
output O1
RANGE_SEL
REQ1
RANGE_SEL
REQ0
Bit
Description
T
VD
REQ
Request to change the maximum time without valid data.
RANGE_SEL
REQ1
Selection of the Integration time and the representation of measured frequency
value.
RANGE_SEL
REQ0
Selection of the Integration time and the representation of measured frequency
value.
The status byte has the following bits:
Bit 7 Bit 6 Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
ST_
GATE
T
VD
ACK
State of the
output O2
State of the
output O1
RANGE_SEL
ACK1
RANGE_SEL
ACK0
Bit
Description
ST_GATE
State of GATE input (0=enabled, 1=disabled)
T
VD
ACK
Acknowledgement T
VD
changed.
RANGE_SEL
ACK1
Acknowledgement of Range Selection, Frequency values are valid.
RANGE_SEL
ACK0
Acknowledgement of Range Selection, Frequency values are valid.