VIGOR ELECTRIC CORP.
VB-4DA
4-Channel Analog Outputs Module
6. Allocation of Buffer Memory (BFM)
Data is transmitted between the VB-4DA and the Main Unit via buffer memories (BFM).
BFM
Description
#0 Output mode select
Default value = H0000 (when the PLC power, OFF→ON)
#1 CH #1 Output data
#2 CH #2 Output data
#3 CH #3 Output data
#4 CH #4 Output data
Default value = 0 (when the PLC power, OFF→ON)
#5 Data holding mode
Default value = H0000 (when the PLC power, OFF→ON)
#30 Model code: K106 (Read only)
[BFM #0] Output mode select:
The value of BFM #0 switches the analog output between voltage and current on each channel. It
takes the form of a 4-digit hexadecimal number. The first digit will be the command for the channel
1 (CH1), and the second digit is for the channel 2 (CH2), and so forth. The numeric values of these
four digits respectively represent the following items:
b15
b0
BFM #0 = H O O O O ==>
Digit #4 Digit #3 Digit #2 Digit #1
CH4
CH3
CH2
CH1
When: O = 0 : Sets the channel to voltage output mode ( 0 V ~ +10 V ).
O = 1 : Sets the channel to voltage output mode ( 0 V ~ +5 V ).
O = 2 : Sets the channel to voltage output mode ( +1 V ~ +5 V ).
O = 4 : Sets the channel to current output mode (+4 mA ~ +20 mA).
O = 5 : Sets the channel to current output mode (0 mA ~ +20 mA).
Switching the output mode resets the I/O characteristics to the factory-set characteristics. Refer to
the section of
<< Charts of D/A Converter Characteristic >>
.
Example: Let the BFM #0 = H 5 2 1 0
CH1 = 0 : Voltage output (0 V ~ +10 V)
CH2 = 1 : Voltage output (0 V ~ +5 V)
CH3 = 2 : Voltage output (+1 V ~ +5 V)
CH4 = 5 : Current output (+4 mA ~ +20 mA)
[BFM #1, #2, #3 and #4]: Output data channels CH1, CH2, CH3, and CH4
BFM #1: Output data of CH1 (Initial value: 0)
BFM #2: Output data of CH2 (Initial value: 0)
BFM #3: Output data of CH3 (Initial value: 0)
BFM #4: Output data of CH4 (Initial value: 0)
[BFM #5]: Data holding mode:
While the programmable controller is in the STOP mode, the last output value in the RUN mode
could be hold. To write a 4-digit hexadecimal number in BFM #5 as follows can choose its analog
output status (at the RUN→STOP condition).
b15
b0
BFM #5 = H O O O O ==>
Digit #4 Digit #3 Digit #2 Digit #1
CH4
CH3
CH2
CH1
When: O = 0 : Sets the channel to hold the output value. (If the PLC RUN→STOP)
O = 1 : Sets the channel to the lowest output (OFFSET) value. (If the PLC RUN→STOP)
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