Modbus TCP gateway
Wieland Electric GmbH | BA000970 | 07/2019 [9855]
57
“Output data (to PLC)” section
Register
Define from and to where in the PLC memory the selected
data should be read and written.
Heartbeat interval (ms)
Defines how often the data sets are to be updated.
Requirement: You have selected the option
Activate heart-
beat interval
(see above).
Register range
Shows the registers in the PLC to which the process data is
written.
“Input data (from PLC)” section
Selection list 1
Set automatically: Determines the transmission method.
Value required for master mode:
samosPRO reads (Master)
Selection list 2
Defines which of the two modbus commands is used:
•
Read holding registers
:
Activates the
Read holding registers
command (see
"Module commands" table below).
•
Read input registers
:
Activates the
Read input registers
command (see "Mo-
dule commands" table below).
Data set
column
Determines which data are to be written to the PLC or read
from it.
Mark the control boxes for the desired data sets for this pur-
pose.
You will find a detailed description of the data sets here:
Data transferred to the network (network input data sets) [ch.
3.2, p. 19]
Register
column
Define from and to where in the PLC memory the selected
data should be read and written.
Column
heartbeat interval
Defines how often the data sets are to be updated.
"Modbus mode” section
PLC IP address
Device ID
The parameters define from and to where the data in the
Modbus-TCP network are to be read and written:
Maximum refresh time for PLC
Define the maximum rate (or the minimum time interval) for
transmitting the data sets to the PLC. This setting depends
on the processing speed of the PLC. Minimum = 10 ms, ma-
ximum = 65535 ms. The basic setting of 40 ms is suitable for
most PLC
Note: When these values are greater than the heartbeat in-
terval, the
heartbeat interval
will be slowed down to this
value.
Combine samosPLAN
6 with the samosPRO system and transmit the configuration.
More detailed information on the link to the controls: Software manual, chapter "Connecting to
the safety controller"
Write to the PLC
NOTICE
The following restrictions apply when the gateway operates as a master and writes the input data
sets to the PLC:
• The address of the input data sets (preset in samosPLAN
6) must be the same as defined in the
PLC.
