Program listing, Program listing -2 – Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual User Manual
Page 94

Publication 1746-UM003A-EN-P
7-2 Application Examples
Table 7.1 Channel Configuration Worksheet
(With Settings Established for Channel 0)
Program Listing
Since a 7-segment LED display is used to display temperature, the temperature
data must be converted to BCD. The 16-bit data word representing the
temperature value is converted into BCD values by the program shown in the
following illustration.
Bit Definitions:
Bits 0 through 3
Input Type Select
0000 = 100
Ω
Pt. (385)
0001 = 200
Ω
Pt. (385)
0010 = 500
Ω
Pt. (385)
0011 = 1000
Ω
Pt. (385)
0100 = 100
Ω
Pt. (3916)
0101 = 200
Ω
Pt. (3916)
0110 = 500
Ω
Pt. (3916)
0111 = 1000
Ω
Pt. (3916)
1000 = 10
Ω
Cu (426)
(1)
1001 = 120
Ω
Ni (618)
(2)
1010 = 120
Ω
Ni (672)
1011 = 604
Ω
Ni-Fe (518)
1100 = 150
Ω
Potentiometer
1101= 500
Ω
Potentiometer
1110= 1000
Ω
Potentiometer
1111= 3000
Ω
Potentiometer
Bits 4 and 5
Data Format Select
00 = engineering units, x1
(3)
01 = engineering units, x10
(4)
10 = scaled-for-PID (0 to 16383)
11 = proportional counts (-32768 to
+32767)
Bits 6 and 7
Broken Input Select
00 = zero
01 = upscale
10 = downscale
11 = lnvalid
Bit 8
Temperature Units
Select
0 = degrees Celsius
1 = degrees Fahrenheit
Bits 9 and 10
Filter Frequency Select 00 = 28 Hz
01 = 50/60 Hz
10 = 800 Hz
11 = 6400 Hz
Bit 11
Channel Enable
0 = channel disabled
1 = channel enabled
Bit 12
Excitation Current Select 0 = 1.0 mA
1 = 0.25 mA
Bit 13
Cal. Disable
0 = enable
1 = disable
Bits 14 and 15
Lead R. Disable
00 = disable
01 = periodic
10 = always
(1) Actual value at °C is 9.042
Ω
per SAMA standard RC21-4-1966.
(2) Actual value at 0°C is 100
Ω
per DIN standard.
(3) Values are in 0.1° /step or 0.1
Ω
/step for all resistance input types, except 150
Ω
. For the 150
Ω
resistance input type, the values are in 0.01
Ω
/step.
(4) Values are in 1° /step or 1
Ω
/step for all resistance input types, except 150
Ω
. For the 150
Ω
resistance input type, the values are in 0.1
Ω
/step.