B-37
5 Buffer Memory (BFM)
5.4 Details of Buffer Memories
A
Common Items
B
FX
3UC
-4AD
C
FX
3U
-4AD-ADP
D
FX
3U
-4DA-ADP
E
FX
3U
-4AD-PT
-ADP
F
FX
3U
-4AD-TC
-ADP
G
PID Instruction
(FNC 88)
FX
3U
/FX
3UC
Series PLC User's Manual - Analog Control Edition
FX3UC-4AD (4-channel Analog Input)
2. Offset/gain data change
Set offset data and gain data to change the input/output characteristics.
The offset and gain data can be set for each channel. If the voltage input mode is set, write the offset and gain
data in mV. If the current input mode is set, write the offset and gain data in µA.
To change the offset data or gain data, turn on the corresponding bit of BFM #21 (buffer memory for input
characteristics writing).
The data setting range is shown in the following table:
*1. The offset and gain values should meet the following condition:
Gain value - Offset value ≥ 1000
*2. The offset and gain values should meet the following condition:
30000 ≥ Gain value - Offset value ≥ 3000
3. Caution regarding offset/gain data change
• If the analog value direct indication mode is used, the input/output characteristics cannot be changed.
• Even if the input/output characteristics are changed, the actual input valid range will not be changed:
from -10V to +10V for the voltage input mode, and from -20mA to +20mA for the current input mode.
• Even if the input/output characteristics are changed, the resolution will not be increased.
→ For a detailed description of input/output characteristics change, refer to Chapter 6.
5.4.15 BFM #61 to #64: Addition data
Setting range: -16000 to +16000
Initial value: K0
Numeric data type: Decimal (K)
If the addition data (BFM #61 to #64) is set, the set data will be added before storing the channel data (BFM
#10 to #13), peak data (BFM #101 to #104, BFM #111 to #114), or data history (BFM #200 to #6999).
1. Caution regarding addition data setting
• To use the addition data, be sure to turn on the data addition function (b0 of BFM #22).
• When setting the lower limit error data (BFM #71 to #74) or the upper limit error data (BFM #81 to #84),
add the addition data (BFM #61 to #64) to the error data to be set.
Voltage input (mV) Current input (µA)
Offset data
-10000 to +9000
*1
-20000 to +17000
*2
Gain data
-9000 to +10000
*1
-17000 to +30000
*2