Rockwell Automation 1771-OFE/B Analog Output Module User Manual - Manual (Page 30)

3-4
Publication 1771Ć6.5.30 - November 1998
Description
Decimal Bit
(Octal Bit)
Word
09 (11)
When set (1), indicates negative maximum scaling value for Channel 3. When
reset (0), indicates positive maximum scaling value for channel 3.
10 (12)
When set (1), indicates negative minimum scaling value for Channel 4. When
reset (0), indicates positive minimum scaling value for channel 4.
Word5
continued 11 (13)
When set (1), indicates negative maximum scaling value for Channel 4. When
reset (0), indicates positive maximum scaling value for channel 4.
12Ć14 (14Ć16) Reserved
15 (17)
When set (1), tells the module to expect binary data. When reset (0), signifies
fourĆdigit BCD data.
At power-up, the module’s microprocessor assumes default
conditions of:
•
positive data words
•
no scaling
•
BCD data
The module’s microprocessor receives these values if you do not
enter data into the configuration word:
The voltage or current value at one of the module’s outputs is
directly proportional to the value specified in that channel’s data
word. The output scale is divided into 4095 parts, which means that
as the data word is incremented or decremented, the output signal is
incremented or decremented 1/4095 of the full scale.
Table 3.B shows the incremented voltage or current assigned to each
bit for the four different output scales. For example, if the data word
for Channel 1 contains the value 0000 0111 1111 1111 (2047
decimal), the output for Channel 1 would be 2047/4095 or
approximately 1/2 of the full scale.
Table 3.B
Output Ranges and Resolution
Nominal Range Unscaled Code Range Actual Output Range ∆ V/Bit or ∆ I/Bit
1 to 5 volts 0 to 4095 1 to 5.00V +0.1% 0.976 mV/Bit
0 to 10 volts 0 to 4095 0 to 10.00V +0.1% 2.44 mV/Bit
Ć10 to +10 volts Ć4095 to +4095 Ć10 to +10.00V +0.1% 4.88 mV/Bit
4 to 20 mA 0 to 4095 4 to 20.00 mA +0.1% 0.0039 mA/Bit
0 to 50 mA 0 to 4095 0 to 50.00 mA +0.1% 0.0122 mA/Bit
Default Configuration
Data Format