
3.27.7.1
Structure
The communication takes place via the I/O area of the head module. The head module
sends via the output area a request telegram to the module. This responds with the
requested data within the input area of the head module. Depending on the used head
module this may take several cycles to complete, until the data are received in the input
area. To ensure the consistency of all measured values, which originate from the same
measurement, are stored in the module under one
. For input and
output data the telegram has a length of 16byte and the following structure:
Byte
Function
B0
B0: Header byte 0
n
Bit 3 ... 0:
‘Status communication’ on page 319
n
Bit 6 ... 4: Telegram type
n
Bit 7: 0 fix reserved
B1
B1: Header byte 1
n
ID of the measurand (1 ... 41)
Chapter 3.27.6 ‘Measurands’ on page 316
–
Each measurand one
ID
is assigned. The access to the measured value of a measurand hap-
pens by means of the corresponding
ID
B2
B2: Header byte 2
n
Bit 3 ... 0: Data set ID (DS-ID) of the measured value (1 ... 15)
n
Bit 7 ... 4: Length of the user data (1 ... 12)
B3
B3: Header byte 3 -
Common status
n
Bit 0: Frequency
F_MAX
exceeded
n
Bit 1: Frequency
F_MIN
undershot
n
Bit 2: Temperature
T_MAX
exceeded
n
Bit 3: Voltage
VRMS_MAX
exceeded
n
Bit 4: Voltage
VRMS_MIN
undershot
n
Bit 5: Efficiency
PF_MIN
undershot
n
Bit 6: Current
IRMS_MAX
exceeded
n
Bit 7: reserved
D00
D00 ... D11: User data:
n
User data for data to be sent and received
...
D11
Via the header byte (bit 3 ... 0) the status of the communication can be determined. On
error no user data are transferred i.e. the length of the user data is 0. Please note that
low error IDs are overridden by higher error IDs.
Status
Designation
0x00
OK (no error)
0x01
Error: No new measured values available
0x02
Error:
DS-ID
0x03
Error: Telegram length
0x04
Error:
Frame
too big
Telegram
Status communication
VIPA System SLIO
Analog Input
031-1PA00 - AI1x 3Ph 230/400V 1A > Process data communication
HB300 | SM-AIO | | en | 17-05
319