User`s manual

6-8 Series 90™-30 CPU with Embedded PROFIBUS Interface – November 2004 GFK-2334A
6
Read Module Header (5)
The Read Module Header command retrieves Network Diagnostic Information for the
device.
Read Module Header Command Block – Basic Example
The following command block accomplishes the following:
Get Module Header Data
Return the COMMREQ Status Word to %R10—%R13.
Return the Device Status to %R251—%R275.
Word Dec (Hex) Definition
Word 1 4 (0004) Length of command Data Block
Word 2 0 (0000) Always 0 (no-wait mode request)
Word 3 8 (0008) Memory type of COMMREQ status word (%R)
Word 4 9 (0009) COMMREQ status word address minus 1 (%R10)
Word 5 0 (0000) Reserved
Word 6 0 (0000) Reserved
Word 7 5 (0005) Read Module Header command number
Word 8 8 (0008) Memory type to write response (%R)
Word 9 250 (00FA) Starting Address to write response (response written to %R251)
Word 10 12 (000C) Size of response area, 12 for slave
(Word 7) Command Code: Word 7 specifies the Command code for the COMMREQ to
be executed. Read Module Header = 5
(Word 8) Local PLC - Memory Type: Words 8—9 specify the location in the PLC where
the response will be written. Values for Word 8 are listed on page 6-4.
(Word 9) Local PLC - Memory Starting Address: Word 9 is a 0-based offset that
determines the starting address in the local PLC in which the response is to be written.
The value entered is the offset (0-based) from the beginning of PLC memory for the
memory type and mode specified in Word 8. This offset will be either in bits, bytes, or
words depending on the mode specified (for example, if Word 8=16 and Word 9=2, the
starting address will be %I17). Valid ranges of values depend on the PLC’s memory
ranges.
(Word 10) Response Memory Size: Word 10 specifies the size of the memory block for
the response. The Response Memory Size is 12 words. If the Response Memory Size is
set smaller than 12, the COMMREQ will fail with a 7 in the COMMREQ Status Word. The
user is responsible for assuring that this area is large enough to contain the requested
data without overwriting other application data