Mitsubishi Electric MELSEC FX-2DA User manual

USER'S GUIDE
JY992D52801C
FX-2DA
SPECIAL FUNCTION BLOCK
This manual contains text, diagrams and explanations which will guide the reader in the correct installation
and operation of the FX-2DA special function block and should be read and understood before attempting
to install or use the unit.
Further information can be found in the FX PROGRAMMING MANUAL and FX SERIES HARDWARE
MANUAL.
●The FX-2DA analog special function block has two output channels. The output channels take a digital value
and output an equivalent analog signal. This is called a D/A conversion. The FX-2DA has a maximum
resolution of 12 bits.
●The selection of voltage or current based input/output is by user wiring. Analog ranges of -10 to 10V
(resolution: 5mV), and/or 4 to 20mA (resolution: 20µA) maybe selected.
●FX programmable controllers versions 2.0 or later (those with serial number 13XXXX or larger) are
required; as these units have the TO/FROM applied instructions in their instruction set. Data transfer
between the FX-2DA and the FX base unit is by buffer memory exchange. There are 32 buffer memories
(each of 16 bits) in the FX-2DA.
●The FX-2DA occupies 8 points of I/O on the FX, FX2C expansion bus. The 8 points can be allocated from
either inputs or outputs. The FX-2DA draws 30mA from the 5V rail of the base unit or powered extension
unit.
INTRODUCTION
1

1.1 External dimensions Weight : Approx. 0.5kg (1.1 lbs) Dimensions : mm (inches)
Any connection to these terminals
may damage the FX-2DA.
125 (4.92) 140 (5.51)
63 (2.48)
73 (2.87) 1
0 ( 0.39)
95 (3.74)
Extension cable
and connector 24V LED
D-A LED
*4 Connect the ground terminal on the FX-2DA with
the ground terminal on the base unit of the
programmable controller. Use class 3 grounding
on the base unit, if available.
*1 Use a twisted pair shielded cable for the analog
output. This cable should be wired away from
power lines or any other lines which could induce
noise.
Caution;
(a) The same output channel cannot drive current
and voltage output loads at the same time!
(b) Shorting the voltage output terminals may da-
mage the unit!
FX-2DA special function block
V
V
I
I
+
-
+
-
*2
Groove for
35mm (1.38)
wide DIN rail
2-5.5mm (0.22)
hole
M3.5 (0.14)
terminal screws
Wiring
2
*2 Apply 1-point grounding at the load side of the
output cable (class 3 grounding: 100 Ωor less). If
electrical noise is caused from grounding,
disconnect from grounding.
*3 If electrical noise or a voltage ripple exists at the
output, connect a smoothing capacitor of 0.1 to
0.47µF, 25V.
CH1
DC/DC
converter +15V
AG-15V
+24V
0V
DC24V ±10% 130mA
*4
PC
Extension cable
Class 3
Grounding
(100 Ωor less)
V
V
I
I
+
-
+
-
CH2 Current output
*2
*1
Recorder,
etc.
Inverter,
etc.
*3
*1
Voltage output

Voltage or current outputs can be individually selected with each output
terminal. There are a total of 2 output points.
18ms for 2 channels (normal speed), 3.5ms for 2 channels (high speed).
DC -10V to +10V
(external load: 1kΩ
to 1MΩ)
Voltage = -2048 to +2047
±1% full scale (10V range)
Specification
24V DC ±10% 130mA
(external power supply)
5V DC, 30mA
(internal power supply from base unit)
Voltage output
Item
Environment specifications
Specification
Same as those for the FX base unit
Analog circuits
Digital circuits
Item
Item
Max. convertible
output range
Digital input
Overall accuracy
Conversion speed
Resolution
Current output
5mV (10V full scale 1/2000)
DC+4mA to +20mA
(external load: 500 Ω or less)
Current = 0 to +1000
±1% full scale (20mA range)
20µA (20mA full scale 1/1000)
Factory Presets
Load:
= 10kΩΩ
ΩΩ
Ω
(voltage
Output)
= 250ΩΩ
ΩΩ
Ω
(current
Output)
Analog output
+2047
+10V
+ 5V
- 5V
-10V
-2000 -1000
-2048
-10.24V
+10.235V
Digital input
Gain and offset can be adjusted using the procedure described in chapter 4.
0 1000
Analog output
+20mA
+ 4mA
Digital input
INSTALLATION NOTES AND USAGE
3
3.1 Environment specification
3.2 Power supply specifications
3.3 Performance specifications
Analog output continued...
0 +1000 +2000

Specification
Photo-coupler isolation between analog and digital circuits.
DC/DC converter isolation of power from FX base unit.
No isolation between analog channels.
8 points taken from the FX expansion bus
(can be either inputs or outputs)
Item
Isolation
Number of occupied I/O
points
ATTENTION FOR WHEN SWITCHING SYSTEM ON/OFF
Due to the inevitable timing difference of the DC24V for the analog circuits and other power lines of the
base unit, the output of the FX-2DA special function block may behave erroneously before settling down
to operational conditions in approximately 1sec. Therefore, ensure that this behavior is taken into account
such that the end performance of the system is not degraded.
(example)
Power switch
Miscellaneous
DC24V
supply FX-2DA special
function block
cut analog lines
before switching External analog
machine

BFM
*# 0
*# 1
*# 2
# 3-# 4
*# 5
# 6
# 8-#19
In BFM's (buffer memory) with an “ * ”, data
can be written from the programmable cont-
roller using the TO command.
These BFM's should always be given when the
programmable controller goes from STOP to
RUN. Buffer memory (BFM's) are reset to their
default settings upon power on.
BFM
*#20
#25-#28
#29
#30
#31
*#21
*#22
*#23
*#24
●The buffer memory also handles information
used to adjust the gain and offsets of the FX-
2DA unit. Status of the unit such as errors
are also available.
●From BFM #29 and #30, data can be read
via the FROM command.
●Offset value : the actual output value when
the digital input is 0.
●Gain value : the actual output value when
the digital input is +1000.
contents
channel Initialization (Default = H00)
channel 1
channel 2
Reserved
Last data reset (Default = 0)
Reserved
selection of A-D
conversion speed
see note
Reserved
Gain/offset adjust prohibit
Initial value (0,1)
Offset/gain
setting command G2 O2 G1 O1
Pro-
hibit Permit
b3 b2 b1 b0
Reset all to default default value: 0
Offset data (in mV or µA units)
default value: 0
Gain data (in mV or µA units)
default value: 5,000
Reserved
Error status (See next page)
Identification code K3010 (See next page)
Reserved
*# 7
When set to 0, normal
speed is selected 18ms
When set to 1, high
speed is selected 3.5ms
3.4 Allocation of buffer memories (BFM)

(1) Channel Selection
Switching between voltage and current output modes. The value of BFM #0 switches the analog output
between voltage and current on channels CH1 and CH2. It takes the form of a 2-character HEX number.
The least significant character controls CH1 and the other controls CH2.
Control of each O HEX character of
HOO
O=0 Voltage output (-10V to +10V)
O=1 Current output (+4mA to +20mA)
Example : H10 CH1 : Voltage output CH2 Current output
:
:
(a)
(b)
(c)
(d)
(2) Last data reset
If the programmable controller is changed to the STOP state, the FX-2DA will continue to output the last
value. To reset the output to the offset value, set the HEX characters of BFM #5 to one of the appropriate
settings below:
H01 : CH2=Hold, CH1=Reset
H10 : CH2=Reset, CH1=Hold
H11 : CH2=Reset, CH1=Reset
Both channels are held when BFM #5 = H00.
(3) Digital to Analog conversion speed change
By writing 0 or 1 into BFM #7 of the FX-2DA, the speed at which D-A conversion is performed can be
changed. However the following points should be noted:
Note :
●
The conversion speed does not depend on the number of channels being used.
●
On power up, the FX-2DA is set for normal speed conversion and BFM #7 contains 0.
(4) Adjusting Gain and Offset Values
When BFM #20 is set to K1, all settings in the buffer memory are reset to their default settings. This
allows the buffer memory settings to be set from the beginning again when many settings have
been corrupted.
If (b1, b0) of BFM #21 is set to (1, 0), gain and offset adjustments are prohibited. This is to prevent
inadvertent misuse by the operator. To adjust the gain and offset, (b1, b0) of BFM #21 must have
the values (0, 1). The default is set at (0, 1).
Each time a TO instruction is used to send data to BFM #22 (gain/offset setting command), the
designated gain and offsets of each channel (G2 O2 G1 O1) are adjusted with the values in
BFM #23 and #24. This action causes the adjustments to be written to internal non-volatile EEPROM
memory. Limit this action to as little as possible to preserve the life of the EEPROM memory.
Gain and offset values in BFM #23 #24 are set in units of mV orµA. Due to the resolution of the unit,
the actual response will be in steps of 5mV or 20µA.
:
:

ON
When any of b1 to b3 is ON D/A conversion
is stopped for the error channel
Offset/Gain data in EEPROM is corrupted or
adjustment error
D/A converter or other hardware failure
FX-2DA MODE switch is not set to READY.
Digital input value or analog output is outside
the specified range.
Bit
b 3 : Hardware error
b 8 : Not READY
b12: Offset/Gain adjust
prohibit
(5) Status information BFM #29
(6) Model code number BFM #30
The identification code for a Special Block is read using the FROM command.
The identification code for the FX-2DA unit is K3010.
The PC can use this facility in the program to identify the special block before commencing any data trans-
fer from and to the special block.
OFF
Hardware normal
READY mode
Permit-(b1, b0) of BFM #21 is
set at (1, 0).
●Values of BFM #0, #5, #21, #23 and #24 are stored in EEPROM memory of the FX-2DA. BFM #23
and BFM #24 are only copied when the gain/offset setting command BFM #22 is used. Also, BFM
#20 causes resetting of the EEPROM memory. The EEPROM has a life of about 10,000 cycles
(changes), so do not use programs which frequently change these BFMs.
●Because of the time needed to write to the EEPROM memory, a delay of 300ms is required between
instructions that cause a change to the EEPROM.
Therefore, a delay timer should be used before writing to the EEPROM a second time.
CAUTION
Bits b4 to b7, b9, b11 and b13 are undefined.
DC 24V power supply failure
Prohibit-(b1, b0) of BFM #21 is set at (1, 0).
No error
Offset/Gain data normal
Power supply normal
Analog output value is normal.
b 0 : error
b 1 : Offset/Gain error
b 2 : Power abnormality
b10: Range error

Offset is the 'Potion' of the calibrated line, identified
at a digital value of 0.
(d) Positive offset
(e) Zero offset – default (4-20mA default is 4mA)
( ) Negative offset
NOTE : If the MODE switch is not set to a channel number, the FX-2DA is regarded as being in the
READY status and no adjustments can be made.
7. Set the FX-2DA MODE switch to READY to complete gain and offset adjustment.
6. Repeat operations 3 to 5 for each channel you wish to use.
5. Press the GAIN button once. The gain value is output. Use the UP/DOWN switch to reach the desired
offset value.
4. Press the OFFSET button once. The offset value is output. Use the UP/DOWN switch to reach the desired
offset value.
3. Set the FX-2DA MODE switch to output CH1.
2. Connect the load and voltmeter or ammeter to the CH1 terminals.
1. Power up the system the FX base unit can be in either RUN or STOP mode.
Offset and gain can be used independently or together. Reasonable offset ranges are -5V to +5V or
-20mA to 20mA, and gain-offset difference 1V to 15V or 4mA to 32mA. Gain and offset can be adjusted by
software in the FX base unit (see program example 2) or by the switches on the FX-2DA (with the aid of a
voltmeter/ammeter).
●Bit device's b0, b1 of the gain/offset BFM (#21) should be set to 0, 1 to allow adjustment.
Once adjustment is complete these bit device should be set to 1, 0 to prohibit any further changes.
●Channel initialization (BFM #0) should be set to the nearest range, i. e. voltage/current etc.
〈〈
〈〈
〈GAIN〉〉
〉〉
〉〈〈
〈〈
〈OFFSET〉〉
〉〉
〉
Analog
Digital
1000
Gain value
(a) (b)
(c)
Gain is the angle or slope of the calibration line
identified at a digital value of 1000.
(a) Large gain– low reading resolution
(b) Zero gain-– default 5V or 20mA
(c) Small gain – high reading resolution
Analog
Digital value 0
Offset value
Digital
(f)
(e)
(d)
DEFINING GAIN AND OFFSET
4
f

In the following example, channel CH1 is set to voltage output, while CH2 is set to current output. The FX-
2DA unit is connected at the position of special function block No.1. If the programmable controller is
changed to the STOP mode, the last data sent will remain and the outputs will hold.
Output
range
normal
5 EXAMPLE PROGRAM
5.1 Basic program
The ID code for the special function block at position
“1”is read from BFM #30 of that block and stored at
D4 in the FX base unit. This is compared to check the
block is an FX-2DA, if OK M1 is turned ON. These
two program steps are not strictly needed to perform
an analog output. They are however a useful check
and are recommended as good practice.
The analog output channels (CH1, CH2) are set up
by writing H10 to BFM #0 of the FX-2DA.
Output data normal
The operational status of the FX-2DA is read from
BFM #29 and output as bit devices at the FX base
unit.
(D0 →BFM #1 (output to CH1))
(D1 →BFM #2 (output to CH2))
M8000
RUN
monitor
K1
M0
D4
D4
K30
K3010
K1
CMP
FROM(P)
K1H10K0K1TO(P)
K2
K1
D0
K4M10
K1
K29
K1
K1
TO
FROM
M18M10
NO
error READY
M20 M3
M1
●Set CH1 setting to D0
(-2,000 to +2,000)
●Set CH2 setting to D1
( 0 to +1,000)

TO(P)
TO(P)
5.2 Using gain and offset in a program
I/O characteristics of the FX-2DA can be adjusted by changing the gain and offset parameters. These can
be changed by the switches of the FX-2DA with the aid of Voltage & Current meters or simply changed by
writting these settings from the programmable controller.
Only the gain and offset values in the memory of the FX-2DA need be adjusted. A voltmeter or an ammeter
for the analog output is not needed. A program for the programmable controller will be needed however.
The following is an example; changing the offset value to 0mA and gain value to 20mA on output channel
CH2 of the FX-2DA connected as block No.1.
Example: Adjusting gain/offset via software settings
X010
M0
T0
T1
K1
K1
H10
K1
K0
K21
K1
K1
K1K0K22K1TO
TO(P)
TO(P)
TO(P)
TO(P)
K1
K1
K1
K1
K23
K24
K22
K21
K0
K20000
HC
RST
K2
K1
K1
K1
M0
K1
●Adjustment start.
●(H10) →BFM #0 (initialize input channels)
In the program shown at left, the programmable
controller should be in RUN status, and MODE
switch of the FX-2DA in the READY position.
●(K1) →BFM #21
BFM #0 should be of HEX value H10, and (b1,
b0) of BFM #21 should be (0, 1).
●(K0) →BFM #22 (offset/adjust)
Reset adjust bits.
T0 K4
●(K20000) →BFM #24 (gain)
●(K0) →BFM #23 (offset)
This statement may be omitted if BFM #23 is already
at its default value.
●(HC) →BFM #22 (offset/gain set)
A delay of 300ms may be needed between setting
BFM #0 and #22 (see section 3.4“caution”)
●Adjustment end.
●(K2) →BFM #21
BFM #21 gain/offset adjust prohibit.
M0SET