AMPLIFIER PARALLEL INTERFACE SPECIFICATION

Transcription

1 AMPLIFIER PARALLEL INTERFACE SPECIFICATION INTRODUCTION A parallel interface connector is fitted at the rear of the amplifier. In multi-unit systems, all of the parallel interface connectors are bussed together to give a single 25-pin connector that provides the interface for the entire system. The status of an individual unit within a system is accessed by applying the appropriate address to the four-bit binary address lines. In single-unit systems the interface is permanently addressed and the address lines are not used. The following colour coding is used in the connector pinout tables. GREEN RED BLUE ORANGE An output signal indicating normal operation An output signal indicating a fault condition An output signal for information only An input signal T Issue K Page 1

2 Parallel interface connector 1. Connector type: 25-pin D Female at rear of amplifier Conn. 1 1 DC POWER Indicates that the unit has valid DC supply rails. 0V=DC not OK, +5V=DC OK. 2 FWD POWER Indicates that the unit s output power is greater than approximately 1% of the nominal full output power. 3 OVERTEMP Indicates if the unit is in an over-temperature condition. This is a self-resetting condition. 0V=RF Power<1%, +5V=RF Power>1%. 0V=Not Overtemp, +5V=Overtemp. DC POWER LED. Green = OK. Not lit = FAULT or unit not switched on. FWD POWER LED. Green = RF output is present. Not lit = RF output not present. OVERTEMP LED. Red = OVERTEMP Not lit = OK This indicator is the logical OR of the status of all of the DC supply rails inside the amplifier and of each individual plug-in module in the associated PSU (if the PSU is external to the amplifier). Operates by detecting the RF forward output voltage. An Overtemp sensor is fitted to every heat generating module in the system (PAs, combiners, drivers, regulators). If any of these switches activates it shuts off the amplifier (in multiamplifier systems this shutoff is system-wide if the Overtemp originates from the final combiner unit). The FAULT line is also asserted, and an OVERTEMP status shows only on the unit which originated the shutdown. T Issue K Page 2

3 Conn. 1 4 OVER DUTY This applies to pulsed amplifiers only. It indicates 0V=Not Overduty, if the unit is in an over-duty +5V=Overduty or over maximum pulse width condition. Over-duty means that the chosen combination of GATE dutycycle and RF input level 5 GAIN CONTROL 6 REFLECTED POWER LIMIT exceeds the preset limits. A control signal of 0 to +5V applied to this pin controls the gain of the amplifier over approximately 10dB range. This applies to CW amplifiers with gain foldback protection. If the reflected power reaches the preset limit the amplifier gain is reduced and the REFLECTED POWER LIMIT pin goes high. 7 VFWD This is an analogue DC voltage representing a sample of the forward voltage at the output of the Analogue control input. 0V = maximum gain. +5V = minimum gain. For remote manual gain control, a 100-ohm potentiometer may be connected between the +5V AUX, GND, and GAIN CONTROL pins (wiper to the GAIN CONTROL pin). 0V=Not limiting, +5V=limiting. Analogue status output. 0V = No detected forward power 2.5V=> Full rated power OVERDUTY LED. Red = OVERDUTY Not lit = OK No local indication or control in standard build. REFL LIMIT LED. Red = Refl power limiting is active. Not lit = Refl power level is below the set limit. No local indication in standard build. OVER DUTY limits the pulse width and duty-cycle to a safe level. This is non-latching protection. Gives approximately 10dB continuous gain reduction range. It is designed to have minimal effect on the noise figure of the amplifier. Not available in multi-amplifier bussed systems. The preset reflected power limit is set at the factory. T Issue K Page 3

4 Conn. 1 amplifier. (approximately). Note that VFWD has an Output resistance approx 470 output impedance of 470- ohms. ohms, so take care not to load it down. 8 VREFL This is an analogue DC voltage representing a sample of the reflected voltage at the output of the amplifier. Note that VREFL has an output impedance of 470- ohms, so take care not to load it down. 9 FAULT This is a logical ORing of one or more DUTYLIMIT, OVERTEMP, MISMATCH fault status conditions. 10 TRG/GT SELECT 11 SHUTDOWN STATUS Used in special amplifiers only. SHUTDOWN STATUS provides readback of the SHUTDOWN control applied to pin 19, for safety interlock use. Analog Status Output 0V = No detected reflected power 0.8V = Full rated power into a 2:1 load mismatch (approximately). Output resistance approx 470 ohms. 0V=Not Fault, +5V=Fault 0V= Shutdown not asserted +5V=> Shutdown asserted. No local indication in standard build. No local indication in standard build, since individual faults have their own indicators. SHUTDOWN LED. Red = shutdown is active. Not lit = OK. In multi-amplifier systems, FAULT indicates a fault in any unit in the system, not just in the unit that is currently addressed. However, the unit that originated the fault will also show the type of fault. In some amplifiers this pin is used for FWD POWER LIMIT status instead of TRG/GT select. 12 ADDRESS This indicates that the SELECTED LED. The local SELECTED LED T Issue K Page 4

5 Conn. 1 SELECTED addressed unit has been 0V= Invalid address found and is presenting its +5V=> Valid address status outputs onto the interface bus. signal is 470 ohms when high 13 ADDR3 This is one of the four digital ADDRESS inputs. When these inputs correspond to the dip-switch address available on the rear panel, the output signals related to this unit are driven onto the parallel interface. This is the MSB. 14 ENABLE STATUS This indicates whether the unit has been locally Enabled such that it will respond to applied Gate/PTT and RF input signals. 15 MISMATCH This indicates whether the unit is shut down due the reflected power exceeding the preset factory limit. 16 PTT IN PTT is a pull-down version of GATE. The two signals are ORed internally. 17 SYSLINK This is a signal used by any chassis in the system to and >10Kohms when low. Digital Address Input. +5V = Logic 1. Default (4k7 pullup provided internally). 0V = Logic 0. 0V=Standby, +5V=Enabled 0V=Not Mismatched, +5V=Mismatched. Digital control input. Pull down to GND (pin 17) to transmit. Digital status output: 0V= System link is actively Blue = unit addressed. Not lit = not addressed. Indicated by the address DIP switch setting. ENABLE LED. Green = enabled. Not lit = not enabled. REFL POWER LED. Red = unit is shut down due to mismatch. Not lit = OK. No local indication. No local indication. lights on the addressed unit only. The address DIP switch is at the rear of the unit. The ENABLE status line only indicates the position of the manual ENABLE switch on the front of the unit. Therefore, the ENABLE status is not affected by the status of the SHUTDOWN line. Not used in amplifiers rated to tolerate 100% reflection. In multi-unit systems PTT is bussed to all units in the system. T Issue K Page 5

6 Conn. 1 shutdown the rest of the disabling the system. system in certain +5V= System link OK. circumstances. It is used only in multi-unit systems. It may be monitored externally, but must not be loaded or have any external voltage applied to it V AUX This is a +5V DC supply for use in external interface circuitry. 19 SHUTDOWN SHUTDOWN is used to remotely prevent the amplifier from transmitting. 20 GATE IN This is an alternative input to the coaxial GATE input at the rear of the amplifier. The two inputs are connected together internally. 21 GND 22 PSU ADJUST This input may be pulled down to GND to change the main DC supply rail voltage. Aux. power supply output. ~4.7V, 100mA max. Digital Control Input. Pull down to GND (pin 21) to disable the amplifier. Input resistance = 10k ohm pullup. Digital Control Input. Pull to +5V to gate the amplifier on. Input resistance = 10k ohm pulldown. Digital control input. High or open = maximum supply voltage Low or pulled down = reduced supply voltage. Input impedance = 1k ohm pullup. SHUTDOWN LED. Red = shut down. Not lit = not shut down. No local indication. No local indication. Shutdown inhibits transmission but does not switch off the PSU. In multi-unit systems GATE is bussed to all units in the system. Fitted to pulsed amplifiers which normally operate on a 50V DC supply. This control permits the supply voltage to be reduced, to allow operation in low-power CW mode (if applicable). T Issue K Page 6

7 Conn ADDR0 This is one of the four digital Digital Address Input. ADDRESS inputs. When the +5V = Logic 1. Default (4k7 applied address pullup provided internally). corresponds to the dipswitch 0V = Logic 0. address available on the rear panel, the output signals related to this unit are driven onto the parallel Indicated by the address DIP switch setting. interface. This is the LSB. 24 ADDR1 See above. As above Indicated by the address DIP switch setting. 25 ADDR2 See above. As above Indicated by the address DIP switch setting. T Issue K Page 7

8 Parallel interface connector 2. Only included in water-cooled and some customized air-cooled systems Connector type: 25-pin D Female at rear of amplifier Conn. 2 1 PA STATUS 1 Indicates that PA module #1 has output power 0V=RF Power<10%, +5V=RF greater than approximately Power>10%. 10% of its rated power. 2 PA STATUS 2 As above (if PA module is As above 3 PA STATUS 3 As above (if PA module is As above 4 PA STATUS 4 As above (if PA module is As above 5 PA STATUS 5 As above (if PA module is As above 6 PA STATUS 6 As above (if PA module is As above 7 PA STATUS 7 As above (if PA module is As above 8 PA STATUS 8 As above (if PA module is As above 9 OVERDRIVE This indicates if the unit is detecting excessive drive on its RF input. 10 FLOW ERROR If a flow meter is fitted (optional), this indicates if the unit is measuring a low level of water flow to its 0V=Drive level OK, +5V=Drive level excessive. 0V=Flow OK, +5V=Flow is low. PA1 LED. Green = RF power present at PA1 module output. Not lit = Power less that 10% of rated power. OVERDRIVE LED. Continuously lit red = amplifier input is being overdriven and the unit is shut down. Not lit = input level is OK. None This signal is optional, and is available on selected amplifiers only. A flow error does not directly cause a shutdown, since a flow monitor cannot reliably confirm adequate flow in all branches of T Issue K Page 8

9 Conn. 2 output port. the cooling system. For this reason, over-temperature is used as the critical requirement for shutdown. Typically it is intended that the operator would monitor the flow error signal and treat it with suspicion if asserted. The operator would then check temperatures and look for a water system problem before shutting down a critical system. This indicates if the unit is HUMIDITY LED on amplifier sensing a likelihood of 0V=Humidity is OK. +5V=Unit front panel. condensation forming on in danger of condensation RED = humidity warning internal water-cooled forming. Not lit = OK components. 11 HUMIDITY ERROR 12 FWD LIMIT SETTING 13 REF LIMIT SETTING A control signal of 0 to +2.5V applied to this pin sets the automatic level control limit for forward power. Any factory set limit can only be decreased using this input. A control signal of 0 to +2.5V applied to this pin sets the automatic level control limit for reflected power. Any factory set limit can only be decreased Analogue control input. Analogue control input. Less than 2.5V must be applied to reduce the preset factory limit. The amplifier output voltage reacts approximately linearly to this input. Less than 2.5V must be applied to reduce the preset factory limit. T Issue K Page 9

10 Conn. 2 using this input. 14 GND 15 PSU ADJ (LSB) This input may be pulled down to GND to reduce the main supply rail. This is the least significant bit of a 2-bit control. 16 RESET This line is used to reset the latching protection circuits. 17 REMOTE ON/OFF 18 LOCAL ON/OFF STATUS 19 This pin is used internally only. 20 MOISTURE ERROR This line is used to switch the amplifier s power supplies on or off. Indicates the status of the power OFF/STANDBY switch on the PSU front panel, for the addressed amplifier unit. Indicates whether moisture has been detected by one of the sensors inside the amplifier unit. Digital control input. High or open = maximum supply voltage Low or pulled down = reduced supply voltage. Input impedance = 1k ohm pullup. Pull to 0V to reset the latched protection circuits. Open = normal operation. Pull to 0V to switch the power on. Open = off. 0V = switch in OFF position +5V = switch in ON position 0V=No moisture detected, +5V=Moisture detected. REMOTE ON/OFF LED on PSU front panel. Green = Remote ON Red = Remote OFF Indicated by position of switch on PSU front panel MOISTURE LED on amplifier front panel. RED = moisture detected Not lit = OK This signal is optional and is available on selected amplifiers only. See description under connector 1. This signal operates in series with the local (front panel) power on/off switch(es). Connected within the amplifier system only. Carries the PSU OFF control that is activated in response to an OVERTEMP or MOISTURE error status Moisture sensors are fitted at key locations inside the amplifier. If any of these activates it shuts off the DC power supply (in multi-amplifier T Issue K Page 10

11 Conn Not Used 22 Not Used 23 Not Used 24 Not Used 25 Not Used systems this shutoff is systemwide). The FAULT line is also asserted, and a MOISTURE status shows only on the amplifier unit which originated the shutdown. T Issue K Page 11

12 ON ADDRESSING All output signals, except for FAULT, ADDRESS SELECTED and SYSLINK are driven onto their respective connector pins only when a valid address has been applied to the 4-bit address input, and will be high impedance otherwise. FAULT, ADDRESS SELECTED and SYSLINK are diode OR ed system-wide signals. The address for each particular unit is set by a 4-bit dip-switch on the rear panel. If the dip-switch address is set to 15, the chassis will remain selected regardless of the address applied to the address lines. Control signals are not addressable and are generally intended to be bussed to every chassis in parallel. T Issue K Page 12