Allen-Bradley Compact I/O 1769-ADN DeviceNet, Руководство пользователя

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Publication 1769-UM001B-EN-P - October 2002
How Communication Takes Place and I/O Image Table Mapping 2-17
1769-IT6 Thermocouple/mV
Input Module
Input Data
The input data file contains the analog values of the inputs.
Wo
rd
Bit Position
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 Analog Input Data Channel 0
1 Analog Input Data Channel 1
2 Analog Input Data Channel 2
3 Analog Input Data Channel 3
4 Analog Input Data Channel 4
5 Analog Input Data Channel 5
6 OC7 OC6 OC5 OC4 OC3 OC2 OC1 OC0 S7 S6 S5 S4 S3 S2 S1 S0
7 U0 O0 U1 U0 U2 O2 U3 O3 U4 O4 U5 O5 U6 O6 U7 O7
Sx = General status bit for channels 0-5 and CJC sensors (S6 and S7). This bit is set (1) when an error
(over-range, under-range, open-circuit, or input data not valid) exists for that channel. An input data not valid
condition is determined by the user program. This condition occurs when the first analog-to-digital conversion
is still in progress, after a new configuration has been sent to the module. Refer to the
Compact
™
I/O
Thermocouple/mV Input Module User Manual , publication 1769-UM004A-EN-P for additional details.
OCx = Open circuit detection bits indicate an open input circuit on channels 0-5 (OC0 - OC5) and on CJC sensors
CJC0 (OC6) and CJC1 (OC7). The bit is set (1) when an open-circuit condition exists.
Ux = Under-range flag bits for channels 0-5 and the CJC sensors (U6 and U7). For thermocouple inputs, the
under-range bit is set (1) when a temperature measurement is below the normal operating range for a given
thermocouple type. For millivolt inputs, the under-range bit indicates a voltage that is below the normal
operating range. These bits can be used in the control program for error detection. The bits are reset (0) by the
module when within the normal operating range.
Ox = Over-range flag bits for channels 0-5 and the CJC sensors (O6 and O7). For thermocouple inputs, the
over-range bit is set (1) when a temperature measurement is above the normal operating range for a given
thermocouple type. For millivolt inputs, the over-range bit indicates a voltage that is above the normal
operating range. These bits can be used in the control program for error detection.
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