18
Fig. 9
XDI–XDIwin – 15/30J
TOXIC/OXYGEN SENSOR
General Data Sheet: 204D1C Issue Tv4
Technical Sheet
ref C894
Power Supply
15 to 30vDC 24v nominal
Outputs
2 wire 4~20mA output only
3 wire 4~20mA
4 wire CANbus
Relays
Low alarm SPCO
High alarm SPCO 0–5A @ 30v DC
Fault alarm SPCO
Inhibit option during servicing
Logging Intervals – variable time
Roll over/stop
Storage – 2,880 readings
Requires RS232 lead
PC or laptop (dedicated)
Hyperterminal (download from GDS website)
Set up procedure:
Direct 4~20mA 2/3 wire (no processor)
New sensors are supplied ready to connect to a system
with all jumpers inserted. This procedure shows how
to recalibrate as part of routine maintenance or cell
replacement.
The first part is to set up the 4–20mA section which is produced
by the CELL circuit. Note some cells take time to stabilise. If
used as 2 or 3 wire then only steps 1 to 5 are required.
1. Connect the cell to terminal J2 and use +24V, 0V and
4~20mA connections on terminal J10 for 3 wire (or +24V
and 4~20mA for 2 wire – see note)
2. Measure voltage across test pins AG to Vo and adjust
reading to zero mV using offset potentiometer
3. Measure the output current mV=mA at test pins TP1/TP2
and adjust reading to 4mV using 4mA pot
4. Apply span gas to cell and adjust 20mA pot to give correct
mV reading at test pins TP1/TP2. NOTE: at 50% span
gas, the mV reading at TP1/TP2 should be 12mV and the
voltage across test pins AG and Vo should not exceed 1 volt
so that 100% of range is achievable.
5. Remove the span gas and re–adjust 4mA pot to 4mV if
required.
4 wire CANbus / 3 wire 4~20mA
with processor communication
6. With power applied ensure that MPU led is flashing and the
CAN led is on or flashing.
7. Connect RS232 pod to J3 connector and to a PC running
HyperTerminal at 4800 baud. Ensure jumper J29 is fitted
before programming.
8. The terminal output screen shows continuous data output/
commands and allows input from the PC keyboard.
Pressing ‘C’ enters calibration mode
a. Press ‘SHIFT $’ to initialise the sensor and reset to default
“Flam 100% LEL” setting.
b. Then press ‘G’ to change the gas type to match the cell
being used.
NOTE:
the range of the new gas has a default value but
can be changed by pressing ‘R’.
c. Press ‘A’ to change the address of this sensor if required
d. Press ‘N’ to select the number of decimal places to 1 or
2, (ie: dp=1 or dp=2)
e. With no gas applied and 4mV measured at test pins
TP8/TP9 press ‘Z’ to zero the gas reading/see note.
f. Then apply span gas and press ’S’ to enter span mode,
optain correct mV reading for test gas used by adjusting
20mA pot. The displayed reading can be made HIGHER
by pressing ‘H’ or lower by pressing ‘L’
g. Pressing ‘SPACE BAR’ will exit the span mode
h. Press ‘V’ to view log of sensor readings if required
i. Pressing ‘X’ will exit the calibration mode.
Note:
Oxygen cells only use the P+ and Y terminals J2. To
adjust for “zero” it is normal practice to disconnect 1 wire from
the cell and adjust the 4mA pot for a 4mV reading across test
pins TP8/TP9 FOR 3 wire sensors, or for 2 wire sensors use
TP1/TP2. When the cell is reconnected in air at 20.8% oxygen
the span can be adjusted for 17.3mV reading across the same
test pins using 20mA pot.
If an LCD option is fitted then calibration and other settings
using magnets instead of a PC can be achieved
– see over.
Command
Use
A = Set CAN address
Sets the CAN address
G = Select gas type
Select the gas type from a list
Z = Zero
Press when no gas on sensor to give zero
S = Span
Use when calibration gas applied,
H and L change reading
D = Enter calibration date
Enter the calibration date
Y = Toggle auto zero
Auto zero is ON or OFF, small drift is cleared
H = Set high alarm
Sets the high alarm threshold
L = Set low alarm
Sets the low alarm threshold
O = Set over range alarm
Sets the over range alarm threshold
P = List command
List these commands on screen
X = Exit calibration mode
Exit this PC mode
$ = Initialise this sensor
Use on new PCB to set gas type to Flam
U = Alarm direction
Sets rising or falling alarms
R = Range
Allows a change in maximum value
N = Decimal points
Toggles between 1 and 2 decimal places
E = Edit user gas text
Choose gas description
B = Toggle deadband
Deadband of 2.5% can be on or off
F = Toggle fault Input
External fault input contact can be disabled
# = Normally energised
Low /high alarm relays and fault relay can be
made normally energised
V= View gas log
From current log, display how many historical
readings to display, up to 2880
% = Clear gas log
Set all 2880 log readings to 0.00
I = Log interval
Choose how many seconds between each log
reading and whether the log will roll over or
stop at 2880 (60 second interval and 2880
readings = 48 hours)
Содержание 404+ Series
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