VISTEK V1679 single-mode fibre
data transceiver
6
Issue 1
2.
GENERAL PURPOSE OUTPUTS
2.1
Description
Depending on the actual board configuration, the V1679 supports up to 16 General Purpose Outputs. Each
Output is implemented as an earth-free, dry contact Relay switch. Each switch can be configured to operate
either in a 'Normally Open' (short: NO) mode, or in a 'Normally Closed' (short: NC) mode.
The Relays can be identified as little black cubes, lined up in either one group (
V1679/IO
, Group B only) or
two groups (
V1670/OP
, Group A and B) at the rear connector end of the board. The output configuration
Jumpers can be found in front of each Relay. Both Jumper positions (NC or NO) are clearly marked on the
board's silk-screen. The factory default setting for each output is 'Normally Open'.
A Relay will change its state, i.e. its contact will be closed (or opened, depending on the actual Jumper
position!), when either being triggered at the far end (remote site) by a state change of the corresponding
General Purpose Input, or locally via DART.
The polarity of the received control bit for any given output is application dependent, hence an unambiguous
relationship between input and output polarities doesn't exist. One might have to experiment with the NO/NC
Jumper settings in order to get the output polarity right. In case of a power failure however, the Relays will fall
back into their default state as configured by the NO/NC Jumpers because they are non-latching. The last
known 'good' state of each output will be latched in case of a broken transmission line or in case of
disconnecting the transmitter at the far end. The Outputs will resume switching as soon as the connection is
re-established. Note that the Relays are not suitable for switching high-current loads or RF signals.
2.2
Configuration
Each relay within a group is clearly numbered (A1..A8 or B1..B8). Please see section 5.2 'Electrical
Interfaces' to find the corresponding signal pairs for each output at the rear connector.
Normally Open /
Normally Closed
Jumper
B
5
GPI Output
Group Name & Number
Relay
N
C
N
O
Circuit Diagram
N
C
N
O
GPIOn+
GPIOn-
Relay Contacts
Jumper
Board Layout
Rear Panel
Connections
Figure 1 : General Purpose Outputs (Circuit Diagram)