DM16E1 / DM4E1 Operation and Installation Manual - 204-4001-19
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12.
ALARMS AND EXTERNAL CLOCK
The alarm inputs and outputs are available on the same DB9 female connector located on the rear panel.
12.1. Alarm Inputs
The DM16E1/DM4E1 cards are provided with three alarm inputs. The alarm inputs can be visualized by
the DmView or via the Terminal port.
The DB9 connector pinout is presented in Table 16:
Input
Terminal
Pin in DB9
Common
7
Input
8
Common
3
Input
4
Common
5
Input
9
External Alarm1
External Alarm2
External Alarm3
Table 16. Pinout of the DB9 connector for alarm inputs
There are two possibilities for the input to recognize external alarms:
•
The corresponding input pins (7 and 8 for ext. alarm1; 3 and 4 for ext. alarm2; and 5 and 9 for ext.
alarm3) must be interconnected with an inter-pin resistance smaller than 10k ohms. This configuration
takes place during the connection of the alarm relay output of another equipment (for example, a DM705
or a DM706C E1 Multiplexer).
•
The corresponding input pin (8 for ext. alarm1; 4 for ext. alarm2; and 9 for ext. alarm3) can be
connected at –48V. For this condition to be valid, it is necessary to connect the signal ground to the frame
ground (see item 10.1).
12.2. Alarm Outputs
DM16E1/DM4E1 cards are provided with a relay in order to generate alarms. The pinout in the DB9
connector is shown in Table 17. In an alarm situation or in case of power failure, the relay gets pin 6 of
DB9 in short with pin 2 of DB9, and pin 1 remains isolated. When there is no alarm, pin 6 gets in short with
pin 1 of DB9, and pin 2 remains isolated.
Input
Relay terminal
Pin in DB9
Normal operation
Alarm situation or
equipament off
Comum
6
NA
1
NF
2
Pin 6 in short
circuito with pin 1
Pin 6 in short circuito with
pin 2
Alarm Output
Table 17. Pinout of DB9 connector for alarm output
The DM16E1/DM4E1 cards also count on a signaling led for alarms on the front panel.
The alarms generated are discriminated in two categories, according to their priority (high or low).
The discrimination between high- and low-priority alarms is carried out by the Terminal port or by the
DmView – it is not done via the ALARM led located on the frontal panel or via the alarm relay.