Connections
Pin Description
1
Auxilliary DC Supply -ve
2
Auxilliary DC Supply +ve
3
4/5 Common
4
External Reset Input
(Input R)
5
Keyboard Disable Input
(Input K)
6
Neutral
7
Live
8
P2 Relay contacts
9
10
P1A contact
11
P1 Common contact
12
P1B contact
13
14/15 Common
14
Input B
15
Input A
Inputs A and B in Unidirectional mode
In the two Unidirectional modes, the count is incremented or decremented by input A,
whilst the direction is dependent on input B.
In Unidirectional High mode, both inputs are high speed inputs, suitable only for
electronic signal sources, eg. transistors, proximity switches, encoders.
In Unidirectional Low mode, both inputs are low speed inputs (30Hz max), suitable
for contact closure sources, eg. microswitches, relays, pushbuttons. Any contact
noise is removed by filtering. They can also be used for electronic signal sources.
Inputs A and B in Quadrature mode
In Quadrature mode, the count is incremented or decremented depending on the phase
difference between input A and input B.
In this mode, both inputs are high speed inputs, suitable only for electronic signal
sources, eg. transistors, proximity switches, encoders.
Input K (Keyboard Inhibit) and Input R (Reset)
Both inputs are low speed inputs as described above.
Cables
Maximum wire size the connector can accept is:
2.5mm
cross sectional area; 1.8mm diameter. (equivalent 13 AWG solid wire)
2
Any signal cables connected to this device must not exceed 30 metres in length.
If signal cables are installed that are routed outside the building, it will be
necessary to install additional surge protection devices.
4
WARNING: This counter must not be wired the same as
the 7921.
Range
0V - See pin 2, below
Power Supply (see pages 37 & 38)
The counter can be powered by AC mains, in which case pins 1
and 2 provide an Auxilliary supply (+12V DC +20% -10%, 75mA
max recommended) which can be used to power sensors if
required. Alternatively, the counter can be powered by an external
DC source (12-24V DC ±10%, 100mA), connected to pins 1 and 2.
See Input Polarity, page 5
Opto-isolated, 12-240 V ±10% DC or 50/60Hz AC
See Specification, page 2
Opto-isolated, 12-240 V ±10% DC or 50/60Hz AC
See Specification, page 2
This input can be used to disable the front panel buttons, but only if
configured by the Inhibit option. See Programming, page 6
94 to 240VAC ±10% 50/60 Hz
Isolated relay contacts
50/60Hz 300V AC max, 220V DC max
See Specification, page 2
See Relays, page 5
See Input Polarity, page 5
5-30 VDC See Specification, page 2