DDA-4010
IRT Electronics Pty Ltd | www.irtelectronics.com
Page 11 of 21
Revision 01
Alarm Outputs:
Independent, link selectable
9
(links LK1 and LK2), alarms switch to Open Circuit or Ground are available for both
A and B inputs. See
Configuration
section of this manual for relevant link positions. Alarm outputs are via MOSFET
relays limited to 120mA maximum continuous load current.
Alarms trigger on either loss of signal input or if input signal does not match the selected data rate (selected data
rate not applicable if reclocker has been bypassed).
If in the ChAx8 mode, alarm B is non-functional regardless of input B’s status unless automatic changeover mode is
also set. Likewise if in the ChBx8 mode alarm A is non-functional regardless of input A’s status unless automatic
changeover mode is also set.
If in the dual ChAx4-ChBx4 mode, both alarms A and B are functional regardless of whether Automatic Changeover
mode is also set or not. However, if the Automatic Changeover mode is set and one of the inputs were to be lost, if
the other input’s rate does not match the lost input’s set rate, an alarm for that other input is not activated. Only
the lost signal alarm is activated with no signal changeover taking place. This is applicable to the rear assembly
alarm only. When monitoring via SNMP, an alarm is reported in this situation.
NOTE:
9
Alarms are link selectable between switch to Open Circuit or switch to Ground on PCB
revisions ≥ Issue 4 only. Earlier revision PCB’s, such as Issue 3, are not link selectable and are
switch to open circuit alarms only.
1
GND.
2
Alarm A.
3
Alarm B.
