Print Date 31/08/11 Page 13 of 22 E2136-00MA-02
2.2.2 Status Connector
This is a 25 Way D socket SK02 at the rear of the unit. This is used to enable basic external
monitoring and control. Multi-core screened cable, not exceeding 3 metres in length, should be used
for the interconnecting lead.
The lead terminates in a 25 Way free D plug at the Amplifier end which is wired as follows :-
Pin 1
System Normal status output (pulled to ground when good)
Pin 2
Spare status output
Pin 3
Spare status output
Pin 4
Current status output (pulled to ground when good)
Pin 5
DC Supply (PSU) status output (pulled to ground when good)
Pin 6
Fans status output (pulled to ground when good)
Pin 7
Fwd Power Fail o/p(approx. –12dB rel. max o/p - pulled to ground when good)
Pin 8
Fwd Power Low o/p (approx. –2dB rel. set o/p - pulled to ground when good)
Pin 9
Reverse Power High output (approx. 35W - pulled to ground when good)
Pin 10
Heatsink Temperature status output (pulled to ground when good i.e.<90deg.C)
Pin 11
Internal/external power control input (pull to ground for external control)
Pin 12
Mute RF input (pull to ground to mute) – for control not safety purposes
Pin 13
DC supply fused output (+50V dc at 500mA maximum)
Pin 14
Reverse power analogue monitor voltage output (0V to +5V into >1k
Ω
)
approximately 0.7V at 35W
Pin 15
Forward power analogue monitor voltage output (0V to +5V into >1k
Ω
)
approximately 2V at 500W.
Pin 16
CPU status (pulled to ground when good)
Pin 17
Chassis Ground for above inputs and outputs
Pin 18
Chassis Ground for above inputs and outputs
Pin 19
Chassis Ground for above inputs and outputs
Pin 20
Chassis Ground for Safety Interlock input
Pin 21
Safety Interlock input (ground to de-mute)
Pin 22
Chassis Ground for External Power Control Voltage Input
Pin 23
Ext. Power Control Voltage Input (0V to +5V DC for min to max power) >10k
Ω
Pin 24
*Interlock status relay contact
Pin 25
* Chassis Ground for Interlock status relay contact
Any of the ‘pulled to ground when good’ status outputs required to be used, must be returned to a
supply of no greater than 25V and must be limited to drawing no more than 50mA each by additional
external resistance (100
Ω
is provided internally).
All of the ‘ground to operate’ inputs (except pin 21, the safety interlock) are internally pulled up to +5V
via 12k
Ω
and must be fed from a voltage free source of less than 1k
Ω
to ground to operate (open
circuit for a high non-operating state). These inputs are protected against constant application of up to
±
25V dc directly applied.
For the safety interlock, a circuit has to be made between pins 20 and 21, which open-circuits to mute
the Amplifier or short-circuits to de-mute. If there are no external safety interlock switches, a short
direct link is made, this being the state in which any connector is normally supplied. If connections
need to be made to external safety switches, this link is removed and the switches are wired in a
series loop to the connector so that if any switch opens, the link is broken. Note that the safety
interlock provides the most robust, and thus safest, muting of output power. The Mute RF input pin 12
(ground to mute) is intended for control purposes only
and not as part of a safety interlock system
.
! CAUTION !
For the safety interlocks to work correctly, the external switches and link wiring must ‘float’
(i.e. must not be grounded at any point, apart from at the Exciter itself).
The total loop resistance
should not exceed approximately 100
Ω
. The external wiring may also be ferrite loaded for emc
requirements.
