Omega LDP-124 - Manual (Page 9)

Page : 8
8.- WIRING
8.1.- POWER SUPPLY, RECOMMENDED WIRING
POWER SUPPLY
115 Vac (230 Vac Optional).
FUSE and spare fuse .
Main switch
8.2.- PROTECTION FUSES
8.3.- CONTROL LINES, ALARM AND SERIAL OUTPUT
1
8
9
15
Power Fuse
Supply value
230 Vac 0.2 A
115 Vac 0.4 A
TABLE 4
1
9
6
5
A : + Alarm
B : No connection
C : No connection
D : - Alarm
A
B
C
D
Serial RS422 connector Control lines connector Alarm connector
The unit has a protection fuse located on the power supply socket.
If this fuse must be replaced or changed because the power supply
is changed, use the time-lag fuse according to IEC 127/2 with the
values indicated on the table.
1.- Vexc.
2.- Vexc.
3.- Start
4.- GND
5.- GND
6.- Minutes
7.- GND
8.- No connection
9.- Vexc.
10.- Stop
11.- Reset
12.- GND
13.- Seconds
14.- Hours
15.- GND
1.- Serial A.
2.- Serial B.
3.- No connection
4.- No connection
5.- GND
6.- No connection
7.- No connection
8.- No connection
9.- No connection.
8.4.- NOTES
The HOURS, MINUTES & SECONDS inputs are for contact closure to GND, and are pulled up to the auxiliary 15
volt rail through 4.7 K
Ω
.
The STOP, START and RESET inputs are normally configured to be pulled up to the auxiliary 15 volt rail through
1 K
Ω,
but may be internally jumpered to be pulled to GND through 1 K
Ω
, or pulled to GND through a high resistance
of 100 k
Ω
.
Debouncing for 200 mS time constant is normally incorporated on the three control inputs, but may be disabled by
removing internal jumpers.
Vexc is the Excitation Voltage for sensors supplied by the instrument (pins 1, 2 & 9).
The connections to Serial A, Serial B and GND are for the RS422 data output.
Run time uncertainty
The control inputs are sensed eight times per second, but the actual run time clock is incremented or decremented
in synchronism with the built in real time clock once per second.
This means that each start/stop condition may be inaccurate by up to one second.