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CM3 AD/DA Module Buffer Memory

CM3-SP04EAA Buffer Memory​

To write to buffer memory, use the TO instruction.

To read from buffer memory, use the FROM instruction.

Please refer to the table below for writing to and reading from buffer memory.

CM3-SP04EAA Buffer Memory
Memory AddressDetailsDefaultReadWriteLink
HexadecimalDecimal
00H0Channel 1 Digital conversion value (AD)-✓-Digital conversion value
01H1Channel 2 Digital conversion value (AD)-✓-
02H2Channel 1 Precise value (AD)-✓-Precise value
03H3Channel 2 Precise value (AD)-✓-
04H4Channel 1 Percentile value (AD)-✓-Percentile value
05H5Channel 2 Percentile value (AD)-✓-
06H6Maximum alarm status (AD)-✓-Maximum alarm status
07H7Minimum alarm status (AD)-✓-Minimum alarm status
08H8Channel 1 Setup input signal range (AD)0✓✓Setup input signal range
09H9Channel 2 Setup input signal range (AD)0✓✓
0AH10Setup Raw Value digital output (AD)0✓✓Setup raw value digital output (AD)
0BH11Channel 1 Average processing setting value (AD)2000h✓✓Average processing setting value
0CH12Channel 2 Average processing setting value (AD)2000h✓✓
0DH13Channel 1 Maximum alarm setting value (AD)0✓✓Maximum alarm setting value
0EH14Channel 2 Maximum alarm setting value (AD)0✓✓
0FH15Channel 1 Minimum alarm setting value (AD)0✓✓Minimum alarm setting value
10H16Channel 2 Minimum alarm setting value (AD)0✓✓
11H17Channel 1 Digital filter constant (AD)30✓✓
12H18Channel 2 Digital filter constant (AD)30✓✓
13H19DA Enable/Disable setup
(DA conversion)		0✓✓
14H20Channel 1 DA output type
Current: 2 types
Voltage: 4 types		0✓✓DA output type
15H21Channel 2 DA output type
Current: 2 types
Voltage: 4 types		0✓✓
16H22Channel 1 Digital value range0✓✓Digital value range
17H23Channel 2 Digital value range0✓✓
18H24Channel 1 DA Channel Hold/Clear0✓✓Channel Hold/Clear
19H25Channel 2 DA Channel Hold/Clear0✓✓
1AH26Channel 1 Digital output value (DA)0✓✓Digital output value
1BH27Channel 2 Digital output value (DA)0✓✓
1CH28AD/DA Resolution setting0✓✓Resolution setting
1DH29Error Code-✓-Error Code
1EH30Operating System Version-✓-OS Version

Analog-to-digital conversion values, which are stored in buffer memory 0 (00H) and 1 (01H), are stored into the CPU memory to be used with the FROM instruction.

Digital Conversion Value​

  • The digital conversion value is used to save A/D conversion of a digital output value.
  • Data in other areas are displayed depending on the AD/DA resolution setting (offset 28).

14-Bit Resolution​

  • The digital conversion value is expressed by 1-bit of data from 0 ~ 64,000 or -32,000 ~ 32,000.
    • If the digital conversion value is off its range, it is fixed into the range -384 ~ 64,383 or -32,384 ~ 32,383.

16-Bit Resolution​

  • The digital conversion value is displayed by 14-bit data from 0 ~ 16,000 or -8,000 ~ 8,000.
    • If the digital conversion value is off its range, it is fixed into the range -192 ~ 16,191 or -8192 ~ 8,191.

Precise Value​

  • The precise value is used to convert A/D conversion values to precise values.
  • Refer to the table below for the analog input range with its precise value.
Precise Value
Analog InputPrecise Value
4mA ~ 20mA4,000 ~ 20,000
0mA ~ 20mA0 ~ 20,000
+1V ~ +5V1,000 ~ 5,000
0V ~ +5V0 ~ 5,000
-10V ~ +10V-10,000 ~ 10,000
0V ~ +10V0 ~ 10,000

Percentile Value​

  • The percentile value is used to save an analog input value for each channel as a percentile value compared with input signal range.
  • The conversion value is 0 ~ 10,000
    • 0% ~ 100.00%

Maximum Alarm Status​

  • If the A/D conversion value exceeds the maximum alarm setting value, the related channel's bit is ON (1).
Maximum Alarm Status Bit Mapping
000000000000Channel 4Channel 3Channel 2Channel 1

Minimum Alarm Status​

  • If the A/D conversion value is less than the minimum alarm setting value, the related channel's bit is ON (1).
Minimum Alarm Status Bit Mapping
000000000000Channel 4Channel 3Channel 2Channel 1

Setup Input Signal Range​

  • The setup input signal range is used to setup the analog input range for each channel.
  • Refer to the table below for the setup input signal ranges.
Signal Ranges
Input Signal RangeSetting Value
4mA ~ 20mA0
0mA ~ 20mA1
+1 ~ +5V2
0V ~ +5V3
-10V ~ +10V4
0V ~ +10V5

Setup Raw Value Digital Output​

  • Setup range of the digital conversion value to output raw value.
    • Two bits for each channel are assigned.
      • Refer to the table below for bit mapping.
Bit Mapping
Most Significant BitsLeast Significant Bits
00000000Channel 4Channel 3Channel 2Channel 1

14-Bit Resolution​

Conversion Input & Full Value Range
14-Bit Resolution
CodeNormal Input RangeFull Range
00 (0)-8,000 ~ 8,000-8,191 ~ 8,192
01 (1)-8,000 ~ 8,000-8,000 ~ 8,000
10 (2)-192 ~ 16,191-192 ~ 16,191
11 (3)0 ~ 16,0000 ~ 16,000

16-Bit Resolution​

Conversion Input & Full Value Range
16-Bit Resolution
CodeNormal Input RangeFull Range
00 (0)-32,000 ~ 32,000-32,767 ~ 32,768
01 (1)-32,000 ~ 32,000-32,000 ~ 32,000
10 (2)500 ~ 64,5000 ~ 65,000
11 (3)0 ~ 64,0000 ~ 64,000

Average Processing Setting Value​

  • The average processing setting value is used to specify average processing methods.
    • Count average:
      • Upper 1 byte
      • 1 ~ 256
    • Time average:
      • Lower 1 byte
      • 0 ~ 256 (10ms)

Maximum Alarm Setting Value​

  • The maximum alarm setting value sets the maximum value for the alarm.
    • The alarm occurs when the A/D conversion value exceeds the maximum alarm setting value.

Minimum Alarm Setting Value​

  • The minimum alarm setting value sets the minimum value for the alarm.
    • The alarm occurs when the A/D conversion value is less than the minimum alarm setting value.

Digital-to-Analog Output Type​

  • The digital-to-analog output type designates the types of analog signals.
DA Output Type
CodeOutput Type
0000 (0)4mA ~ 20mA
0001 (1)0mA ~ 20mA
0010 (2)+1V ~ +5V
0011 (3)0V ~ +5V
0100 (4)-10V ~ +10V
0101 (5)0V ~ +10V

Digital Value Range​

  • The digital value range is used to set the range of digital values that sequence program specifies.

14-Bit Resolution​

Digital Value Range
14-Bit Resolution
CodeRange
00 ~ 16,000
1-8,000 ~ 8,000
2Current Value: 0 ~ 20,000
Voltage Value: -10,000 ~ 10,000
3Percentage: 0 ~ 10,000

16-Bit Resolution​

Digital Value Range
16-Bit Resolution
CodeRange
00 ~ 64,000
1-32,000 ~ 32,000
2Current Value: 0 ~ 20,000
Voltage Value: -10,000 ~ 10,000
3Percentage: 0 ~ 10,000

Channel Hold/Clear​

  • Channel hold/clear is used to specify the status of the analog output signal when the PLC switches from RUN mode to STOP mode.
Channel Hold/Clear
Hold/ClearSTOP Mode Output
0000 (0)Clear
(Minimum Output)
0001 (1)Hold
(Maintain Last Output)
0010 (2)Half Level
(Medium Output)
0011 (3)Maximum Level
(Maximum Output)

Digital Output Value​

  • The digital output value is used to convert a specified digital value to an analog signal.

Resolution Setting​

  • The resolution setting sets either 14-bit or 16-bit resolution for the digital-to-analog output value.
    • There is no additional task needed to convert the measured value once 14-bit resolution is maintained.
AD/DA Resolution Bit Mapping
Most Significant BitsLeast Significant Bits
DA ResolutionAD Resolution
Channel 4Channel 2Channel 2Channel 1Channel 4Channel 3Channel 2Channel 1
Resolution Code
CodeResolution
014-Bit
116-Bit

Error Code​

Error Codes
Error CodeDescription
0No Error
1System Error
Considered A/S
2No external DC 24V power

Operating System Version​

  • The operating system version indicates the firmware version of the module.