Motorola ACE3600 RTU, Руководство пользователя, Страница: 139 / 379

Digital Output Relay 120/230V Module
10-3
Figure 10-2 ACE3600 High Voltage 12 DO Module – Front Panel
In the High Voltage 12 DO modules, the relays of all outputs (1 through 12) are normally open
(NO) “Form A”.
The physical position of each relay is monitored by the module logic, using a back indication
signal which is connected to the relay’s second contact set. Any contradiction between the
required position and the back indication signal is reported to the CPU and is available to the
user program.
In some applications it is necessary to inhibit relay output operation when attending the site for
safety reasons. In all EE DO relay modules, it is possible to inhibit all relays per DO module.
When a module is configured to enable relay inhibiting, the power to the relays is provided
from the power supply via a dedicated power line (12V DO), controlled from the “12V DO”
input. (The 12V DO TB is located on the front panel of the power supply modules, except for
the low-tier and expansion models.) When the input’s terminals are shorted, the relays are
operational. When the input’s terminals are open, the relays are inhibited (EE relays in 0
position.)
ML relays cannot be inhibited.
Note: In systems with I/O expansion, the power supplies on I/O expansion frames can be
attached via DC cable to the power supply on the previous I/O expansion frame in a daisy-
chain manner, or directly to the main power supply. In this case, the 12V DO control on the
main power supply can control all DO EE relays in the entire RTU that were configured by dip
switch for 12V DO. This enables the user to inhibit all DO EE relays in the entire RTU simply
by removing the plug from the 12V DO control in the main power supply. For more
information, see the I/O Expansion and Expansion Power Supply Module chapters below.