Specifications

Appendix Process Images
A - 6
MITSUBISHI ELECTRIC
STL-AD4-I (ID number 51205051)
The four-channel analog input module STL-AD4-I (for currents from 4 to 20 mA) transmits a 16-bit
measured value and 8 status bits per channel. Accessing the status byte depends on the fieldbus sys-
tem being used.
The digitalized measured value is transmitted in a data word (16 bits) as input byte 0 (low) and input
byte 1 (high) into the process image of the head station/controller.
This value is represented with a 12 bit resolution on bit b3 to b14. Both bits b0 and b1 are set in case
of measurement range underflow, overflow or broken wire.
X: Not used; UV: Measuring range underflow, OV: Measuring range overflow
* In this cases the ERROR-LED of the corresponding channel is lit.
Fig. A-9: Process image of the analog input module STL-AD4-I
NOTE The representation of the process data of some I/O modules in the process image depends on the
fieldbus head station used.
Please take this information as well as the particular design of the respective control/status bytes
included in the description concerning the process image of the corresponding head station.
Input
[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
Measured value X UV/OV
<4.0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0003 H 3 41 H *
4.0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0000 H 0 00 H
5.6 0 0 0 0 1 1 0 0 1 1 0 0 1 X 0 0 0CCC H 3276 00 H
7.2 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 0 1998 H 6552 00 H
8.8 0 0 1 0 0 1 1 0 0 1 1 0 0 X 0 0 2664 H 9828 00 H
10.4 0 0 1 1 0 0 1 1 0 0 1 1 0 0 0 0 3330 H 13104 00 H
12.0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4000 H 16384 00 H
13.6 0 1 0 0 1 1 0 0 1 1 0 0 1 X 0 0 4CCC H 19660 00 H
15.2 0 1 0 1 1 0 0 1 1 0 0 1 1 0 0 0 5998 H 22936 00 H
16.8 0 1 1 0 0 1 1 0 0 1 1 0 0 0 0 0 6660 H 26208 00 H
18.4 0 1 1 1 0 0 1 1 0 0 1 1 0 0 0 0 7330 H 29488 00 H
20 0 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 7FF8 H 32760 00 H
>20 0 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 7FFB H 32761 42 H *
Tab. A-5: Input values and corresponding process values for the STL-AD4-I
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
Input byte 1
UV
OV
X0/10/10/10/10/10/10/10/10/10/10/10/1X
Input byte 0
X: Not used
UV: Measuring range underflow
OV: Measuring range overflow
UV
OV