Specifications

Appendix Process Images
A - 10
MITSUBISHI ELECTRIC
STL-DA2-I (ID number 51205041)
The analog output module STL-DA2-I (two channels, 4 to 20 mA) requires 16-bit data and 8 status bits
per channel.
The digitalized output value is transmitted in a data word (16 bits) as output byte 0 (low) and output
byte 1 (high) via the process image of the head station. This value is represented with a 12 bit reso-
lution on the bits b3 to b14. The three least significant bits (b0 to b2) are not parsed.
Some fieldbus systems can process status information by means of a status byte. As the returned sta-
tus byte of this output module is always zero, it will not be parsed.
X: Not relevant
NOTE
Although the bits b0 to b2 are not relevant, they can be used for the ease of programming (see
table below). The resulting output error will only be marginal.
Fig. A-13: Process image of the analog output module STL-DA2-I
Output
[mA]
Numerical value
Status
byte
(Hex.)
Binary
Hexa-
decimal
Decimal15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
X Output value X X X
4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0000 H 0 00 H
6 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1000 H 4096 00 H
8 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 2000 H 8192 00 H
10 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 3000 H 12288 00 H
12 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4000 H 16384 00 H
14 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 5000 H 20480 00 H
16 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 6000 H 24576 00 H
18 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 7000 H 28672 00 H
20 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 7FFF H 32767 00 H
Tab. A-9: Process values and corresponding output values for the STL-DA2-I
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
Output byte 1
XXX0/10/10/10/10/10/10/10/10/10/10/10/1X
Output byte 0
X: Not used