ProSoft Technology 5204SE-MNET-PDPMV1 User Manual
Page 103
Reference 5204SE-MNET-PDPMV1
♦ ProLinx Gateway
User Manual
Modbus TCP/IP to PROFIBUS DP-V1 Pass-Through Master
ProSoft Technology, Inc.
Page 103 of 235
December 22, 2009
4.4.4 Cyclic I/O Variables, DDTs and DFBs - M340
The following five sections provide a more detailed breakdown of the Variables,
DDTs and DFBs used for transferring PROFIBUS cyclic data.
DFB Read Cyclic Data - M340
The Read Cyclic Data DFB is used to retrieve PROFIBUS cyclic input data from
the 5204SE-MNET-PDPMV1 gateway and bring it back into the processor. This
is the data being received by the PROFIBUS DP-V1 Master from the slave or
slaves on the PROFIBUS network.
MNETDPV1_BASICVAR_ReadCyclicData Variables - M340
This variable structure is the one to use with your control and sequencing logic
when you want to send a request to read PROFIBUS cyclic input data.
Variable Name
Size/Type
Description
Out - Timeout
1
16-bit integer
Used to hold the amount of time in milliseconds to wait for a
response to the Modbus TCP/IP command before assuming
a communication error has occurred and setting the In-
MessageError status bit
Out -
ReadCyclicData
1
Single-bit
Boolean
This is the bit your control and sequencing logic will use to
trigger a cyclic read message. Set this bit to one (1)
whenever no other messages are active and when you
want to update the PROFIBUS cyclic slave input data.
Out - Register
Count
1
16-bit integer
Will hold the total number of 16-bit register words of
PROFIBUS cyclic input data that need to be read. This
value will be the same as what you entered in the PCB
configuration for the [PROFIBUS Master DPV1] Input Data
Size parameter
Out - MailBoxData Multi-variable
nested DDT
For details, see Modbus DDT (page 98).
In - Message
Done
1
Single-bit
Boolean
The DFB will set this bit when the Modbus TCP/IP response
is successfully received and the PROFIBUS cyclic input
data variables have been updated.
In - Message Error 1
Single-bit
Boolean
The DFB will set this bit when the Modbus TCP/IP response
is not successfully received. When this bit is set, it indicates
your control and sequencing logic should retry the
command.