Renesas H8S/2168 User Manual download pdf (Page 15)

Telco alarm interface

A telco alarm interface, as specified in the PICMG 3.0 Revision 2.0 AdvancedTCA Base

Specification, is provided on the SPM’s face plate through a 15-pin male D-shell (DA-15P)

connector.

Redundant Telco alarm

Connect relay outputs in parallel

The Telco alarm and power indicator relay outputs of a redundant pair of SPMs can be

connected in parallel such that the alarm output works when one of the SPMs fails. The

connection scheme is based on the following:

1. External alarm inputs are driven by a contact closure.

2. The NO contacts of the SPM will be open when any of the following conditions are present:

• No alarm condition

• No power to the SPM

• The SPM is inoperative

3. The NO alarm contacts of the SPM will be closed when the SPM is operative and there is an

alarm condition. The NO power indicator contacts will be closed when power is applied.

Input/Output Description

CRITICAL ALARM#

MAJOR ALARM#

MINOR ALARM#

There are three alarm outputs in the telco interface. Each of these is electrically isolated by

a dry contact relay and provides up to 1500 volts of isolation. The relay outputs provide

the SPDT switch action (Normally Open, Normally Closed, and Common relay contacts).

These relays are normally off, and the Renesas H8S/2168 microcontroller must drive the

relay to connect the NO contact to the COMMON contacts. Each relay can handle up to

75 volts DC or 1 Amp of current with a maximum rating of 30 W / 30 VA.

POWER#

There is one power indicator output in the Telco interface. It is electrically isolated by a dry

contact relay and provides up to 1500 volts of isolation. Common and normally open

contacts are provided. The relay is normally off, but it is on when power is applied to the

SPM. The Renesas H8S/2168 microcontroller can drive the relay to override this state. The

relay can handle up to 75 volts DC or 1 Amp of current with a maximum rating of

30 W / 30 VA.

MAJOR RESET#

MINOR RESET#

There are two reset inputs in the Telco interface. Both of the inputs are optically isolated

and provide up to 1500 volts of isolation. The inputs can be switched in a range between

3.3 and 72 volts. These inputs provide reverse polarity protection for the optical isolator.

A logical high on the Renesas H8S/2168 microcontroller GPIO pin corresponds to a

voltage of 0 to +3.3 volts applied at the external input.

See Table 6, “Telco alarm interface connector pin descriptions,” on page 23 for the pinout of the connector.

1 2 ... 10 11 12 13 14 15 16 17 18 19 20 ... 29 30

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Renesas H8S/2168 User Manual Page 15