ProSoft Technology 5204-DFNT-PDPMV1 - Manual (Page 28)

Configuration PDPMV1 ♦ ProLinx Gateway
Protocol Manual PROFIBUS DPV1 Master
Page 28 of 157 ProSoft Technology, Inc.
March 23, 2011
2.2.7 Mailbox Register
0 to 3700, -1 to disable
Enter the database register for DPV1 mailbox messages, or -1 to disable mailbox
messages.
Mailbox messages can be sent through the database to the PROFIBUS Master.
This functionality requires 290 registers of the database. The map of the
database area utilized for this purpose is as follows.
Offset Description
0 This is the handshake word used to tell the PROFIBUS driver when a new acyclic
message is ready to send. If the value at this location is zero (0), no message will be
sent. If the value is not zero, then the PROFIBUS driver will send an acyclic
message using the contents of words 1 through 144. This handshake word should
be set to a non-zero value only after the complete acyclic message is stored in
offsets 1 to 144. After the PROFIBUS driver has added the acyclic message to the
queue, this register will be set to zero (0), so that the message is not repeated and to
indicate that a new acyclic message may be prepared.
NOTE: It would be a good practice to check the value of word 145 to be sure it is set
to zero (indicating that no acyclic messages are awaiting processing) before setting
this word to a non-zero value, triggering an acyclic message. This will help avoid
acyclic data collisions and data loss.
1 to 144 This area holds the acyclic message bytes to send. Please refer to Mailbox
Messaging (page 75) for the format of this data area.
NOTE: The header words (first 32 bytes) are stored in little-endian format and the
gateway will change the order to big-endian format before sending.
145 This handshake word indicates when a new acyclic response message has been
received by the PROFIBUS driver. If the value is zero (0), no response message has
been received. If the value is non-zero, a response message has been received and
stored in words 146 to 289. This data should be transferred by the other gateway
protocol for external processing. After the acyclic message has been externally
processed, a message should be returned through the other protocol that sets this
address to zero, to indicate readiness to receive and process a new acyclic response
message.
146 to 289 This area holds the acyclic message response bytes. Please refer to Mailbox
Messaging (page 75) for the format of this data area. The header words (first 32
bytes) are stored in little-endian format to make it easier to use.
Alarm acyclic messages are sent from the PROFIBUS driver to the database if
this feature is enabled by entering a valid database register in the configuration
file. This feature requires 145 database registers. The format of the data area is
as follows.
Offset Description
0 This is the alarm handshake word. If the value is not zero (0), alarm data is present
in the words 1 through 144. This register should be set to zero after the alarm is
process, so another alarm can be passed through the database. If this register is
zero (0), the database area is ready to receive a new alarm message.
1 to 144 This area holds the alarm acyclic message received by the PROFIBUS Master
device. Please refer to Mailbox Messaging (page 75) for a description of this acyclic
message. The header (first 32 bytes) of the message is stored in little-endian format
to make it easier to process.