Siemens 500 NIM - Manual (Page 95)

NIM Primitives 4-42 SIMATIC TIWAY I Series 500 NIM User Manual
Series 500 NIM Primitive Descriptions (continued)
Symbol Value Definition
HH Attached device operational status
EEEEEEEE EEEEEEEE is a mask as defined by the Request
Primtive and DDDD is defined by the data type being
accessed. The order of return of the blocks is from the
lowest numbered block to the highest. For example, if
blocks 2, 4, and A were requested, the first data block
in the response specifies data which is associated with
block 2, the next data block specifies data which is
associated with block 4, etc.
DD Data
Write and Gather Block Primitive – Code 52. The Write and Gather
Block Primitive specifies which blocks (as defined with Define Block
Primitive 50) will be read. It also allows a user to replace any contiguous
data element locations. The blocks are specified through a 32-bit mask
(EEEEEEEE).
In the bit mask position which corresponds to a block specified in Define
Primitive 50, a bit value of 1 indicates that the block is to be returned. A bit
value of 0 means that the block will not be returned.
You should not request more data than can be returned in a maximum
length Primitive frame. Following the mask are the descriptors associated
with the write function, which is performed before the gather operation.
The response will return the data associated with the requested blocks,
beginning with the lowest block number and increasing to the highest block
number. A data block separator is not provided in the response.
Request: LLLL 52 EEEEEEEE TT AAAA DD ... DD
(repeated)
where EEEEEEEE is 32 bits defined as:
Block Number 1 (hex) Block Number
20 (hex)
. . .
. . .
MSB LSB