LX3V-4AD
6
WECON TECHNOLOGY CO., LTD.
By writing 0 or 1 into BFM #15 of the LX3V-4AD, the speed at which A/D conversion is
performed can be changed.
However the following points should be noted: To maintain a high speed conversion rate, use
the FROM/TO commands as seldom as possible.
NOTES:
When a conversion speed change is made, BFM #1-#4 are set to their default values
immediately after the change. This is regardless of the values they held originally. Bear this in
mind if a speed change will be made as part of the normal program execution.
3)
Adjusting Gain and Offset values
Formula for Gain/Offset: Digital output= (Analog input-Offset)*Constant/ (Gain-Offset)
a)
When buffer memory BFM #20 is activated by setting it to K1, all settings within the analog
special function block are reset to their default settings. This is a very quick method to
erase any undesired gain and offset adjustments.
b)
If (b1, b0) of BFM #21 is set to (1, 0), gain and offset adjustments are prohibited to prevent
inadvertent changes by the operator. In order to adjust the gain and offset values, bits (b1,
b0) must be set to (0, 1). The default is (0, 1).
c)
Gain and offset values of BFM #23 and #24 are sent to non-volatile memory gain and offset
registers of the specified input channels. Input channels to be adjusted are specified by the
appropriate G-O (gain-offset) bits of BFM #22.
Example:
If bits G1 and O1 are set to 1, input channel 1 will be adjusted when BFM #22 is written to
by a TO instruction.
d)
Channels can be adjusted individually or together with the same gain and offset values.
e)
Gain and offset values in BFM #23 #24 are in units of mV or µA. Due to the resolution of
the unit the actual response will be in steps of 5mV or 20µA.
4)
Status Information BFM #29
Bit devices of BFM #29
ON
OFF
b0: Error
When any of b1 to b4 is ON. If
any of b2 to b4 is ON, A/D
conversion of all the channels is
stopped
No error
b1: Offset/gain error
Offset/Gain data in EEPROM is
corrupted or adjustment error.
Offset/Gain data normal
b2: Power source abnormality
24V DC power supply failure
Power supply normal
