Mitsubishi MELSEC-F FX-4AD User manual

●The FX-4AD analog special function block has four input channels .The input channels receive
analog signals and convert them into a digital value.This is called an A/D conversion.The FX-4AD
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
DC (resolution: 5mV), and/or 4 to 20mA, -20 to 20mA (resolution: 20µA) may be selected.
●FX PC versions 2.0 or later (those with serial number 13OOOO or larger) are required as these
units have the TO/FROM applied instructions in their instruction set. Data transfer between the FX-
4AD and the FX base unit is by buffer memory exchange. There are 32 buffer memories (each of
16 bits) in the FX-4AD.
●The FX-4AD 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-4AD draws 30mA from the 5V rail of the FX base unit or
powered extension unit.
This manual contains text, diagrams and explanations which will guide the reader in the correct installation
and operation of the FX-4AD 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.
INTRODUCTION
1
USER'S GUIDE
JY992D52601E
FX-4AD
SPECIAL FUNCTION BLOCK

24V
A-D
POWER
READYCH1
OFFSET
GAIN
CH3
CH2
CH4
V+ COM
I+ FG
CH1
DC24V
+-
+-
I+
COMV+
FG
CH2 CH3 CH4
I+
COMV+
FG I+
COMV+
FG I+
COMV+
FG
1.1 External dimensions weight : Approx 0.5kg (1.1 lbs) Dimensions:mm (inches)
2TERMINAL LAYOUTS
*1 The analog input is received through a twisted
pair shielded cable. This cable should be wired
separately from power lines or any other lines
which may induce electrical noise.
*2 If a voltage ripple occurs during input, or there is
electrically induced noise on the external wiring,
connect a smoothing capacitor of 0.1 to 0.47µF,
25V.
*3 If you are using current input, connect the V+ and
I+ terminals to each other.
*4 If there is excessive electrical noise, connect the
FG frame ground terminal with the grounded
terminal on the FX-4AD.
*5 Connect the ground terminal on the FX-4AD unit
with the grounded terminal on the base unit. Use
class 3 grounding on the base unit, if available.
73 (2.87")
63 (2.48") 95 (3.74")
140
(5.51")
125
(4.92") Mounting
holes
5.5mm
(0.27in.)
dia.
Extension
cable and
connector
10 (0.39")
M3.5 (0.14")
terminal
screws
35mm
(1.38in.)
DIN rail
mounting
slot
I+ FG FG
V+ COM
I+ I+
COM
V+COM
V+
FG
CH2 CH3 CH4
V+ COM
I+ FG
CH1
DC24V
+-
+-
V +
FG
COM
I
+
+
V
+
-
PC
COM
I +
DC24V
DC24V
FG
DC/DC
con
verter
CH1
*3
*4
*5
50mA
DC24V
Class 3
Grounding
(100 or less)
CH4
Voltage input
0 to +/-10V
*1 shielded
*2
Current input
0 to +/-20mA
*1 shielded
100K
100K
200K
AG(analog ground)
100K
100K
250K
+15V
AG
-15V
Extension cable
FX-4AD Analog Input Block

3INSTALLATION NOTES AND USAGE
3.1 General specification
3.2 Power supply specification
3.3 Performance specifications
Analog inputs
Item Specification
General specifications(excluding withstand voltage) Same as those for the FX base unit
Item Specification
Analog circuits 24V DC +/- 10%, 50mA(External power supply from base unit)
Digital circuits 5V DC, 30mA(Internal power supply from base unit)
Item Voltage input Current input
Either voltage or current input can be selected with your choice of input terminal.
Up to four input points can be used at one time.
Analog input range DC -10V to +10V (input resistance:200K Ω). DC -20mA to +20mA (input resistance:250 Ω).
Warning:this unit may be damaged by input
voltage in excess of +/-15V. Warning:this unit may be damaged by input currents in excess of +/-32mA.
Digital output 12-bit conversion stored in 16-bit 2's complement form.
Maximum value:+2047 Minimum value:-2048
Resolution 5mV (10V default range 1/2000) 20 µA(20mA default range 1/1000)
Overall accuracy +/-1% (for the range of -10V to +10V) +/-1% (for the range of -20mA to +20mA)
Conversion speed 15ms/channel (Normal speed), 6ms/channel (High speed)

Preset 0 (-10V to +10V) Preset 1 (+4mA to +20mA) Preset 2 (-20mA to +20mA)
Analog inputs continued.....
Digital
Output
+1600
+1000
+32mA+20mA
-1000
-1600
-20mA-32mA
Current
Input
Current
Input
+1750
+1000
+32
mA
+20
mA
+4
mA
Digital
Output
Miscellaneous
Item Specification
Isolation Photo-coupler isolation between analog and digital circuits. DC/DC converter isolation of power from FX base unit.
No isolation between analog channels.
Number of occupied I/O points 8 points taken from the FX expansion bus (can be either inputs or outputs)
Digital
Output
+10V
+10.235V
Voltage Input
+2047
+2000
-10.24V
-10V
-2000
-2048
NOTE: Preset ranges are selected by an appropriate setting in buffer memory of the analog block.
Current/Voltage input selection must match the correct input terminal connections.

BFM Contents
*# 0 Channel initialization Default = H0000
*# 1 Channel 1 Contains the number of samples (1 to 4096) to
be used for an averaged result. The default
setting for normal speed is 8.
The default setting for high speed is 1.
*# 2 Channel 2
*# 3 Channel 3
*# 4 Channel 4
# 5 Channel 1 These buffer memories contain the averaged
input values for the number of samples entered
for the channel in buffer memories #1 to #4
respectively.
# 6 Channel 2
# 7 Channel 3
# 8 Channel 4
# 9 Channel 1 These buffer memories contain the present
value currently being read by each input
channel.
#10 Channel 2
#11 Channel 3
#12 Channel 4
#13-#14 Reserved
#15 When set to 0, a normal speed is selected of
15ms/ch (default)
When set to 1, a high speed is selected of
6ms/ch
#16-#19 Reserved
3.4 Allocation of buffer memories (BFM)
In buffer memory locations (BFMs) marked
with an "*" data can be written from the PC
using the TO command.
For buffer memories (BFMs) without the "*"
mark, data can be read to the PC using the
FROM command.
Before reading from the analog special
function block, ensure these settings have
been sent to the analog special function
block. Otherwise, the previous values held
in the analog block will be used.
The buffer memory also gives a facility to
adjust offset and gain by software as well
as by panel switches of the FX-4AD unit.
(see note 3)
Offset (intercept): The analog input value
when the digital output becomes 0.
Gain (slope): The analog input value when
the digital output becomes +1000.
BFM b7 b6 b5 b4 b3 b2 b1 b0
*#20 Reset to Defaults and Preset. Default=0
*#21 Offset, Gain Adjust Prohibit. Default=(0,1)Permit
*#22 Offset, Gain Adjust G4 O4 G3 O3 G2 O2 G1 O1
*#23 Offset Value Default=0
*#24 Gain Value Default=5,000
#25-#28 Reserved
#29 Error status
#30 Identification code K2010
#31 Cannot be used
Selection of A-D
conversion
speedseenote2

(1) Channel Selection
Channel initialization is made by a 4 character HEX number HOOOO in buffer memory BFM #0.
The least significant character controls channel 1 and the 4 character controls channel 4.
Setting of each character is as follows:
O = 0: Preset range (-10V to +10V) O = 2: Preset range (-20mA to +20mA)
O = 1: Preset range (+ 4mA to + 20 mA) O = 3: Channel OFF
Example: H3310
CH1: preset range (-10V to +10V)
CH2: preset range (+ 4mA to +20mA)
CH3, CH4: Channel OFF
(3) Adjusting Gain and Offset Values
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.
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).
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.
Channels can be adjusted individually or together with the same gain and offset values.
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.
(a)
(b)
(c)
(d)
(e)
By writing 0 or 1 into BFM #15 of the FX-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.
(2) Analog to Digital Conversion Speed Change

(4) Status information BFM #29
(5) Identification code BFM #30
The identification (or ID) code number for a Special Function Block is read using the FROM command.
The code for the FX-4AD unit is K2010.
The user's program in the PC can use this facility in the program to identify the special function block
before commencing data transfer from and to the special function block.
CAUTION
●
Values of BFM #0, #23 and #24 are copied to EEPROM memory of the FX-4AD. BFM #21 and
BFM #22 are only copied when data is written to the gain/offset command buffer BFM #22. Also,
BFM #20 causes writing to 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 300 ms is required
between instructions that cause a write to the EEPROM.
Therefore, a delay timer should be used before writing to the EEPROM a second time.
NOTE : • b4 to b7,b9 and b13 to b15 are undefined.
Bit ON OFF
b 0: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
b 1:Offset/Gain error Offset/Gain data in EEPROM is corrupted
or adjustment error. Offset/Gain data normal
b 2:Power source abnormality DC 24V power supply failure Power supply normal
b 3:Hardware error A/D converter or other hardware failure Hardware normal
b 8:Not READY FX-4AD MODE switch is not set to READY READY mode
b10:Digital range error Digital output value is less than -2048
or more than +2047 Digital output value is normal
b11:Averaging error Number of averaging samples is 4097 or more or 0 or less
(default of 8 will be used) Averaging is normal (between 1 and 4096)
b12: Offset/Gain adjust prohibit Prohibit-(b1,b0) of BFM #21 is set to (1,0) Permit-(b1,b0) of BFM #21 is set to (0,1)

4DEFINING GAIN AND OFFSET
1.
2.
3.
4.
5.
6.
7.
8.
NOTE:
Power the system up (the FX base unit can be in either RUN or STOP mode).
Set the FX-4AD MODE switch to the first channel number.
Apply the offset analog input to the terminal of the channel.
Press the OFFSET button once. The digital offset value (converted from the analog input value) is
stored in the FX-4AD.
Apply the gain analog input to the input terminal of the channel to be adjusted.
Press the GAIN button once. The digital gain value is stored in the FX-4AD.
Repeat operations 3 to 6 for each channel you wish to use.
Set the FX-4AD MODE switch to READY to complete gain and offset adjustment.
If the MODE switch is not set to a channel number, the FX-4AD is regarded as being in the READY
status and no adjustments can be made.
Offset is the 'Position' of the calibrated line, identified at a
digital value of 0.
(d) Negative offset
(e) Zero offset - default : 0V or 4mA
( ) Positive offset
f
Analog
Digital
Offset value
(f)(e)(d)
0
1000
Digital
(a) (b)
(c)
Gain value
Analog
OffsetGain
Offset and gain can be set independently or together. Reasonable offset ranges are -5 to +5V or -20mA to
20mA, and gain values 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-4AD (with the aid of a voltmeter/ammeter)
●Bit device's b1, b2 of the gain/offset BFM #21 should be set to 0, 1 to allow adjustment.
●Once adjustment is complete these bit devices 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 determines the angle or slope of the calibration line,
identified at a digital value of 1000.
(a) Small gain-- Large steps in digital readings
(b) Zero gain --- default : 5V or 20mA
(c) Large gain - Small steps in digital readings

5EXAMPLE PROGRAM
5.1 Basic program
In the following example channels CH1 and CH2 are used as voltage inputs. The FX-4AD block is connected
at the position of special function block No.0. Averaging is set at 4 and data registers D0 and D1 of the PC
receive the averaged digital data.
K0 K30 D4 K1
M8002
Initial
pulse
K2010 D4 M0
K0 K0 H3300 K1
K0 K1 K4 K2
K0 K29 K4M10 K1
K0 K5 D0 K2
M1
M18M10
The analog input channels (CH1, CH2) are setup by
writing H3300 to BFM #0 of the FX-4AD.
The ID code for the special function block at position
"0" is read from BFM #30 of that block and stored at
D4 in the base unit. This is compared to check the
block is an FX-4AD, if OK M1 is turned ON. These
two program steps are not strictly needed to perform
an analog read. They are however a useful check
and are recommended as good practise.
The number of averaged samples for CH1 and CH2
is set to 4 by writing 4 to BFM #1 and #2 respectively.
Do not execute the pulse.
If there are no errors in the operation of the FX-4AD,
then the averaged data BFM's are read.
In the case of this example BFM #5 and #6 are read
into the FX base unit and stored at D0 and D1. These
devices contain the averaged data for CH1 and CH2
respectively.
The operational status of the FX-4AD is read from
BFM #29 and output as bit devices at the FX base
unit.
READY
NO
error
CMP
TO P
FROM
FROM
TO
FROM

5.2 Using gain and offset in a program
The gain and offset of the FX-4AD can be adjusted using push-button switches on the input terminal of the PC.
It can also be adjusted using software settings sent from the PC.
Only the gain and offset values in the memory of the FX-4AD need be adjusted. A voltmeter or an ammeter
for the analog input is not needed. A program for the PC will be needed however.
The following is an example of changing the offset value on input channel CH1 to 0V and the gain value to 2.5V.
The FX-4AD block is in the position of block No.0 (i.e. closest to the FX base unit).
Example: Adjusting gain/offset via software settings
X010 SET M0 • Adjustment start.
M0 TO PK0 K0 H0000 K1
TO PK0 K1 K1K21
• (H0000) →BFM #0 (initialize input channels)
Enter the instructions on the left and RUN the PC with
the MODE switch of the FX-4AD set to READY.
• (K1) →BFM #21
BFM #21 (gain/offset adjust prohibit) must be set to
permit with (b1, b0) = (0,1).
TO K0 K0K22 • (K0) →BFM #22 (offset/gain adjust)
Reset adjust bits.
K1
T0K4
T0 TO PK0 K23 K0 K1
TO PK0 K2500 K1K24
TO PK0 H0003 K1K22
T1K4
• (K0) →BFM #23 (offset)
• (K2500) →BFM #24 (gain)
• (H0003) →BFM #22 (offset/gain adjust)
3 = 0011 i.e. O1 = 1, G1 = 1.
Therefore channel 1 is adjusted.
RST M0
TO PK0 K21 K2 K1
T1 • Adjustment end.
• (K2) →BFM #21
BFM #21 gain/offset adjust prohibit.