Rockwell Automation 1794-IT8,D17946.5.7 Thermocouple/Millivolt Input Module - Manual (Page 38)

5–4 How Communication Takes Place and I/O Image Table Mapping with the DeviceNet Adapter
Publication 1794-6.5.7 – April 1997
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 Dec. Bit
00 01 02 03 04 05 06 07 10 11 12 13 14 15 16 17 Octal Bit
Read Word 7 Channel 5 Input Data
Read Word 8 Channel 6 Input Data
Read Word 9 Channel 7 Input Data
Read Word 10 Overrange Bits Underrange Bits
Read Word 11 0 0 0 0 0
Bad
Cal
Cal
Done
Cal
Range
0 Diagnostics
Pwr
Up
Bad
Structure
CJC
over CJC
Under
Thermocouple/mV Input Module (1794-IT8) Write
Dec. Bit 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Octal Bit 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
Write Word 1 8-Bit Calibration Mask
Cal
Clk Cal hi
Cal lo
Filter Cutoff FDF Data Type
Write Word 2 Thermocouple 3 Type Thermocouple 2 Type Thermocouple 1 Type Thermocouple 0 Type
Write Word 3 Thermocouple 7 Type Thermocouple 6 Type Thermocouple 5 Type Thermocouple 4 Type
Where: FDF = fixed digital filter bit
Word/Bit Descriptions for the 1794-IT8 Thermocouple/mV
Input Module
Word
Decimal Bit
(Octal Bit)
Description
Read Word 1 00–15 (00–17) Reserved
Read Word 2 00–15 (00–17) Channel 0 Input data
Read Word 3 00–15 (00–17) Channel 1 Input data
Read Word 4 00–15 (00–17) Channel 2 Input data
Read Word 5 00–15 (00–17) Channel 3 Input data
Read Word 6 00–15 (00–17) Channel 4 Input data
Read Word 7 00–15 (00–17) Channel 5 Input data
Read Word 8 00–15 (00–17) Channel 6 Input data
Read Word 9 00–15 (00–17) Channel 7 Input data
Read Word 10 00–07 (00–07) Underrange bits – these bits are set if the input signal is below the input channel’s minimum range.
08–15 (10–17) Overrange bits – these bits are set if 1), the input signal is above the input channel’s maximum range,
or 2), an open detector is detected.
Read Word 11 00 (00) Cold Junction sensor underrange bit. – this bit is set if the cold junction temperature is below 0 o C.
01 (01) Cold Junction sensor overrange bit. – this bit is set if the cold junction temperature is above 70 o C.
02 (02) Bad Structure – this bit is set if there is an invalid thermocouple type selected.