PlaneWave Electronic Focus Accessory EFA Kit The EFA control box can be mounted to the back plate of any PlaneWave telescope OTA (12.5 through 24 inches). The EFA Kit plugs into the temperature sensors and fan control systems that are built into each telescope. A Hand Control is provided to control an optional Focuser or Rotator when standing at the eyepiece. The EFA kit comes with PlaneWave Interface (PWI3), a software package that controls all EFA functions from a PC. Cables and adapters are provided to attach the EFA kit to a PC. The EFA kit is ASCOM compatible. The EFA kit automates focusing on the optional Hedrick Focuser, or IRF90 rotating focuser. Monitors temperature (primary-mirror and OTA back-plate). Controls the fans built-in to CDK telescopes. Ensure you have the proper EFA kit selected for your telescope below. 125901-Kit is for CDK12.5 OTAs. 240901-Kit is for CDK14, CDK17, CDK20, and CDK24 OTAs. Technical Specifications EFA PC Port Protocol Overview Message Packet: SOM Start Of Message byte must start every message packet. SOM = 59 = 0x3B NUM Number of Bytes is calculated by: NUM = [(Packet Byte Count) – 3] (Note: The bytes SOM, NUM, and CHK are not counted in NUM) SRC Source Address RCV Receiver Address CMD Command See below for a list. DA1 DATA1 Optional data byte, Some commands require data. DA2 DATA2 Optional data byte, Some commands require data. DA3 DATA3 Optional data byte, Some commands require data. CHK Checksum The last byte of the message packet is a Checksum. It is calculated by summing the bytes of the packet, excluding the SOM and CHK, and taking the Least Significant Byte of the two’s complement. Examples are below. When data bytes combine to represent an integer, the MOST-SIGNIFICANT data byte is sent first. All messages require the Receiver to respond. If the no data response is necessary, the Receiver will responsd by sending a meesage with the CMD it received. NOTE: THE EFA RESPONDS TO ANY MESSAGE RECEIVED, EVEN INVALID COMMANDS! Port Settings: Baud Rate: 19200 Parity: None Data bits: 8 Stop bits: 1 RTS/CTS Flow Control PC waits for the CTS to be clear PC enables the RTS PC sends message packet PC clears the RTS Focuser Scale Factor: (115134.42 Encoder Counts) = (1 mm Focuser Travel) Nominal Focuser Travel: 33 mm = 3799422 Encoder Counts Focuser Encoder = 0 when racked completely in Standard Addresses Device Decimal Hex PC Computer 32 0x20 HC Hand Control 14 0x0D FOC Focuser 18 0x12 FAN Fan Controller 19 0x13 TEMP Temperature Sensor 18 0x12 Commands Command Description CMD (Hex) Send Data Response Data Send Sample (Hex) Respond Sample (Hex) MTR_GET_POS Get position 0x01 3 bytes (encoder position) 3B 03 20 12 01 CA 3B 06 12 20 01 00 00 00 C7 Encoder Position = 0 MTR_GOTO_POS2 GOTO position 0x17 3 bytes (encoder position) 1 byte (1=OK) Goto Position = 0x140000 = 1310720 MTR_OFFSET_CNT Set current focuser encoder position. Often used to set focuser encoder to Zero. 0x04 3 bytes (encoder position) 1 byte (1=OK) 3B 06 20 12 04 14 00 00 B0 Set Encoder Position = 0x140000 = 1310720 3B 04 12 20 04 01 C5 MTR_GOTO_OVER Determine if the motor is moving during a GOTO? 0x13 1 byte (255=YES, 0=NO) 3B 03 20 12 13 B8 3B 04 12 20 13 FF B8 Goto is Over MTR_SLEWLIMITMAX Set the Maximum Slew Limit. 0x1B 3 bytes 1 byte (1=OK) 3B 06 20 12 1B 3B 82 60 90 Set Min Slew Limit = 0x3B8260 = 3900000 3B 04 12 20 1B 01 AE MTR_SLEWLIMITGETMAX Returns the Maximum Slew Limit in encoder ticks 0x1D 3 bytes (encoder position) 3B 03 20 12 1D AE 3B 06 12 20 1D 3A 4F A5 7D Maximum Slew Limit = 0x3A4FA5 = 3821477 MTR_PMSLEW_RATE Move the motor positive. Motor will stop when the Max Slew Limit is reached. 0x24 One byte for the speed (stop to fastest) = (0x00 to 0x09) 1 byte (1=OK) 3B 04 20 12 24 09 9D Go Positive Top Speed 3B 04 12 20 24 01 A5 MTR_NMSLEW_RATE Move the motor negative. Motor will stop when the Min Slew Limit is reached. 0x25 One byte for the speed (stop to fastest) = (0x00 to 0x09) 1 byte (1=OK) 3B 04 20 12 25 09 9C Go Negative Top Speed 3B 04 12 20 25 01 A4 TEMP_GET Get the temperature of one sensor 0x26 One byte address(Primary=0, Ambient=1, Secondary=2) 3 bytes (byte1=address, [byte2 & byte3] = Temperature…See Formula Below) 3B 04 20 12 26 01 A3 Request Temp for ambient 3B 05 12 20 26 5C 01 46 Temp=5C01 (see below for conversion to Celcius) FANS_SET Set the fans, on or off. 0x27 1 byte (1=ON, 0=OFF) 1 byte (1=OK) 3B 04 20 13 27 01 A1 Set FANS=ON 3B 04 13 20 27 01 A1 FANS_GET Get the fans state, on or off. 0x28 1 byte (0=ON, 3=OFF) 3B 03 20 13 28 A2 3B 04 13 20 28 00 A1 FANS=ON MTR_GET_CALIBRATION_STATE Determine if the focuser as been calibrated. Useful for Handcontrol and PWI Focus software. 0x30 1 byte (0x40) 1 byte (0=NO, 1=YES) 3B 04 20 12 30 40 5A 3B 04 12 20 30 01 99 Motor = calibrated. MTR_SET_CALIBRATION_STATE Set the calibration state for the focuser. Useful for Handcontrol and PWI Focus software. 0x31 2 bytes (Calibrated = 40 01) and (Not = 40 0) 1 byte (1=OK) 3B 05 20 12 31 40 01 57 Set calibration = true 3B 04 12 20 31 01 98 MTR_GET_STOP_DETECT Determine if Motor will stop when the focuser hits a physical hardstop. 0xEE 1 byte (1=YES, 0=NO) 3B 03 20 12 EE DD 3B 04 12 20 EE 01 DB Stop Detect = enabled MTR_STOP_DETECT Set the controller to stop when focuser hits a physical hardstop. 0xEF 1 byte (1=YES, 0=NO) 3B 04 20 12 EF 01 DA Set Stop Detect = enabled 3B 03 12 20 EF DC MTR_GET_APPROACH_DIRECTION Get the approach of motor during a goto 0xFC 1 byte (0=negative, 1=positive=default) 3B 03 20 12 FC CF 3B 04 12 20 FC 00 CE Motor is set to approach from positive, this is default. MTR_APPROACH_DIRECTION Get the approach of motor during a goto 0xFD 1 byte (0=negative, 1=positive=default) 1 byte (1=OK) 3B 04 20 12 FD 00 CD Set APPROACH = positive, this is default. 3B 04 12 20 FD 01 CC GET_VERSION Get Firmware Version 0xFE 2 bytes (byte1=Major, second byte2=minor) 3B 03 20 12 FE CD 3B 05 12 20 FE 01 05 C5 Version = 1.5 Convert Temperature to Celsius The response request for temperature is 3 bytes byte1=address, byte2 & byte3 are used to calcuate the temperature If there is no sensor for the address requested, the response bytes are 0x7F7F (Primary=0, Ambient=1, Secondary=2) Conversion of the two received bytes to Celsius int rawTemp = byte2*256 + byte3bool tempIsNeg = falseif(rawTemp > 32768){tempIsNeg = truerawTemp = 65536 – rawTemp}int intPart = RawTemp / 16int fractionDigit = (RawTemp – intPart) * 625 / 1000float celciusTemp = intPart + fractionDigit / 10if(tempIsNeg) celciusTemp = -celciusTemp PC Port Cable – RJ45 and DB9 2 Receive Data 3 Transmit Data 5 Signal Ground 7 Request To Send 8 Clear To Send In the Box PlanWave Electronic Focus Accessory EFA Kit Manuals & Warranty 1-Year Coatings & 2-Year Mechanics & Electronics Warranty
