HCS DAC-42A - General Communication Information; Special Information for Bus Activation; General Information about TADR (Telegram Address); General Information about CMD (Command) and SADR (Slave Address)

DAC-42(A)-x-PN
Page 41
DAC-42(A)-x-PN Manual
Revision: 1.0 22.01.2024
7 General communication information
7.1 Special information for bus activation
If communication via Profinet is required, there must be a connection to the power supply; supply via USB is not sufficient.
The Profinet-Node connected to the PLC (Error LED is off). In addition, parameter E22 must be set to "on" or “1”.
7.2 General information about TADR (Telegram Address)
TADR is a value which may be written (changed) with each cycle but changing of this value is optional and not mandatory.
The value will be defined by the Profinet-Master.
The purpose is to either check the telegrams by the master or also in order to force sending of a new telegram from the
node.
The design of the node is made in a way that the slave or slaves (module or modules in case of multi-slave version) are
only responding if a received message from the master contains changed (different) data compared to the previous
message.
So TADR can be used to force a response from a slave for example in order to get an update on the current status of the
slave even if the other data in the message remain unchanged.
TADR value is valid in the range of 0 to 255 or in hexadecimal 0x00 to 0xFF.
7.3 General information about CMD (Command) and SADR (Slave Address)
The SADR is used to address different slaves which are connected to the same Profinet-
node. In case of the DAC-4x(A) the possibility of a Multi-Slave Nodes is not possible. The
slave Address in the telegram must always set to “0” or “1”
Different ways of communication between master and slaves (modules) are possible. The difference is in the CMD
instruction.
CMD = 6: Writing of a single parameter-ID to the DAC-4x(A). The Profinet node has only one slave
(one DAC-4x(A) connected. In this case SADR is set to 1.
□ Chapter „8.3.1 CMD = 6, Master Write single parameter (7 bytes) ”, page 44
CMD = 3: Reading of one or more parameters with parameter-ID in rising order. The Profinet node has only
one slave (one DAC-4x(A) connected. In this case SADR is set to 1
□ Chapter „8.1.1 CMD = 3, Master Read parameters (7 bytes)”, page 42
CMD = 15: This instruction allows writing or reading of a (pre-defined) set of parameters. The set of parameters
itself is depending on the software version of the DAC-4x(A); refer also to
□ Chapter „9.5 CMD = 15, structure of Profinet telegram definition, depending on SW Versions“,
page 49
For more information please to □ Chapter „9 Complex commands”, page 47
It is possible to „mix“ the instructions CMD = 3, CMD = 6 and CM = 15 for the DAC-4x(A).