NORD Drivesystems BU0710 - Manual (Page 20)

NORDAC SK 700E manual Posicon special extension
20 BU 0710 GB
3.7 Relay signals
The Posicon positioning card is endowed with two multi-function relays, each of which can be assigned one
function in a parameter. It is not possible to establish AND or OR circuits between any of these functions. The
following functions are available on both relays:
- Reference point
The relay signals that a valid reference point has been established. The relay drops out when reference
point tracking is started. As soon as the reference point is found the relay pulls up. The state the relay will be
in when the inverter voltage is switched on depends on the setting made in P606 (if the "save position"
option has been selected the relay will have picked up when the inverter is switched on, otherwise it will
have dropped out).
- Final position
The inverter will use this function to indicate that the setpoint position has been reached. The relay picks up
when the amount by which the actual position deviates from the setpoint position is smaller than the value
set in the "Relay hyst." parameter and when the current frequency is smaller than the + 2Hz minimum
frequency (P104).
- Reference position
The relay will close the circuit when the actual position is greater than or equal to the value defined in the
"Relay position" parameter. The relay will be released again when the actual position value becomes less
than "Relay reference position" – "Relay hyst". The sign is taken into account.
[Multifunction relay pulls up when p
act
> p
ref
and drops out when p
act
< p
ref
– p
hyst
]
- Absolute reference position
The function "absolute reference position" is basically similar to the function "reference position" except that
the actual position is processed as an absolute (unsigned) value. The relay is operated when the actual
position exceeds the parameterised value or drops below the value of the same but negative amount.
[Multifunction relay picks up when |p
act
| > |p
ref
| and drops out when |p
act
| < |p
ref
| – p
hyst
]
- Position array value
The relay picks up whenever any of the positions parameterised between 1 and 63 is either reached or
overshot. This function is available even if "position array" was not selected as position setpoint mode.
- Relay P541
Operation of the multifunction relay is defined in parameter P541. As a result unused relays can be
assigned other jobs via a field bus as required.
- Final reference position
The relay will close the circuit when the amount by which the actual position deviates from the reference
position is smaller than the value set in the "relay hyst." parameter.
[Multifunction relay picks up when |(p
ref
- p
act
)| < p
hyst
]
- Final absolute reference position
The relay closes the circuit when the absolute value of the amount by which the absolute actual position
deviates from the absolute reference position becomes smaller than the value set in the "relay hysteresis"
parameter.
[Multifunction relay pulls up when |(|p
vef
| - |p
act
|)| < p
hyst
]
All relay functions are available even if the system is not operated in the position control mode
(P600 = 0).