IPSeries IPM4 Mobile Radio Product Owner’s Manual Date Released: January 9, 2003 Document #: 516-80485-POM Revision: B (Special Release) Copyright 2002 IPMobileNet, Inc.
TABLE OF CONTENTS SECTION 1: THEORY OF OPERATION ................................................................................. 3 General Block Diagram................................................................................................ 3 General Block Diagram Definitions..................................................................... 3 IPM4 Mobile Radio Section Descriptions................................................................... 5 Microcontroller .............................
SECTION 1: THEORY OF OEPRATION General Block Diagram General Block Diagram Definitions For increased data security, the modem supports the Federal Government developed Digital Encryption Standard (DES) data encryption and decryption protocols. This capability requires installation of third party, Internet Protocol (IP) compliant DES encryption and decryption software on the system. The IPM4 mobile radio is comprised of two (2) circuit boards, the digital board and the RF board.
SECTION 1: THEORY OF OPERATION The RF circuit board contains the following sections: Transmit Processing Circuitry that amplifies the analog audio signal from the modem and uses it to modulate the voltage controlled oscillator (VCO) and 10 MHz reference oscillator in the injection synthesizer section. Modulating the VCO and reference oscillator simultaneously results in a higher quality FM signal. Injection Synthesizer Provides programmable, ultra stable signals for the radio.
SECTION 1: THEORY OF OPERATION IPM4 Mobile Radio Section Descriptions The IPM4 Mobile Radio works within a frequency range of 450 to 470 MHz and requires a 1/4-wavelength antenna. This section provides detailed descriptions of each of the sections within the IPM4 Mobile Radio. Refer to Appendix A to view the IPM4 Mobile Radio Circuit Board Diagram. Microcontroller The microcontroller (U30) is a major component of the radio as it manages the operation of the radio.
SECTION 1: THEORY OF OPERATION Modem The single-chip modem circuit converts parallel data to an analog audio waveform for transmission and analog audio from a receiver to parallel data. In addition to the modem functions, the chip provides forward error detection and correction (FEC), bit interleaving and Viterbi Soft Decision Algorithms for more robust data communications. The microcontroller section controls the modem operation. Address bus, address/data bus, and control lines operate the modem chip.
SECTION 1: THEORY OF OPERATION Receiver 1 Front-End This section contains components that include several RF Bandpass filters, a low-noise amplifier, and a MMIC mixer. Incoming signals pass through one (1) pre-selector filter (FLT7) that selectively provides a high degree of out-of-band signal rejection. A low-noise amplifier (U3) amplifies the selected signals and is followed by an image and noise reject filter (FLT8). The output from FLT8 passes through a mixer (U4).
SECTION 1: THEORY OF OPERATION The lower op amp (U70C) amplifies the signal from the low pass filter and applies it to the VCO via the VCOMOD output. Pot RV1 and RV2 are used to adjust maximum deviation. Injection Synthesizer The dual synthesizer chip (U38) is the major contributor of the injection synthesizer. This device contains the key components of a phase locked loop (PLL), including a prescaler, programmable divider, and phase detector.
SECTION 2: FACTORY TEST PROCEDURE Equipment List The following table lists the equipment required to perform the IPM4 Mobile Radio Factory Test Procedure: QTY 2 1 DESCRIPTION MANUFACTURER PC’s One for Mobile One for Base Service Monitor – Communication Test Set Windows 9X w/ IPMessage AVR MODEL HP HP8920B or equivalent Tektronix Fluke 77 or equivalent Astron RM35A Tektronix TDS 460A Pasternack PE7021-40 or equivalent 1 Digital multi-meter 1 DC power supply w/ ammeter, 13.
SECTION 2: FACTORY TEST PROCEDURE Programming and Configuring Mobile Radio Once the appropriate equipment for performing the factory test are gathered, perform the following steps to program and configure an IPM4 Mobile Radio: Step 1 Enter the following information on the Test Data Sheet (see Appendix B): Radio Serial number Date test being performed Tester's Name Step 2 Program the radio to the current Firmware revision using the AVR programming utility.
SECTION 2: FACTORY TEST PROCEDURE Adjustment / Alignment Procedures Receiver Injection Perform the following steps to adjust the receiver injection and injection frequency: Step 1 While monitoring the receiver injection frequency at RXINJ1, adjust potentiometer R81 for minimum frequency error of +/- 100Hz. Record this value on the Test Data Sheet. Step 2 While monitoring the 44.
SECTION 2: FACTORY TEST PROCEDURE Receiver 2 Perform the following steps to adjust receiver 2: Step 1 Inject an on-frequency carrier signal with an amplitude of -80 dBm, modulated with a 1 kHz test tone at +/- 5.0 kHz deviation into Receiver 2's antenna port. Step 2 While monitoring the voltage at RSSI2 Test Point with a DMM, adjust trimmer capacitor CV4 to midway between the points where the oscillation stops.
SECTION 2: FACTORY TEST PROCEDURE Transmit Data Perform the following steps to adjust transmit data: Step 1 Use IPMessage to set the transmit power to 0. Step 2 Using the x=2000,n command of IPMessage to generate transmit data messages while observing the transmitted signal on the HP RF communications test set, adjust pot R33 for minimum frequency error while transmitting data messages. Step 3 Turn potentiometer RV1 fully counterclockwise. Step 4 Adjust RV2 for deviation of 4.9 kHz.
SECTION 2: FACTORY TEST PROCEDURE Receive Data Perform the following steps to verify the receive data performance: Step 1 Using the DOS ping command on the PC connected to the radio, ping the network controller to generate uplink and downlink data messages. The following command will generate one Hundred 500 character messages: >;Ping 192.168.3.
SECTION 2: FACTORY TEST PROCEDURE Step 5 Verify the timing characteristics are identical to the plots in the next section, Uplink Hardware Timing Verification. Step 6 At the base station monitor PC, verify that all the data quality readings are 240 and higher. Step 7 Move the scope probes to monitor the timing at the mobile radio as described in Downlink Hardware Timing Verification. Generate test messages by pinging the IPNC from the PC attached to the radio.
SECTION 2: FACTORY TEST PROCEDURE Uplink Hardware Timing Verification Figure 2-1 below displays an oscilloscope plot of an uplink data message from the mobile to the base station. Channel 1 is connected to the base station's RSSI (XXX-12), channel 2 is connected to the base station's recovered modulation, and channel 3 is connected to the base station's modem chip select line. The scopes acquisition mode is high-resolution.
SECTION 2: FACTORY TEST PROCEDURE Figure 2-2 displays another oscilloscope plot of an up-link data message from the mobile to the base station. As in the last plot, channel 1 is connected to the base station's RSSI (J5-12), channel 2 is connected to the base station's recovered modulation test point, and channel 3 is connected to the base station's modem chip select line (U16-13). The scope's acquisition mode is now in the peak detect mode.
SECTION 2: FACTORY TEST PROCEDURE Downlink Hardware Timing Verification Figure 2-3 displays a plot of the downlink timing characteristics. Channel 1 is connected to RSSI, channel 2 is connected to recovered audio, and channel 3 is connected to the modem CS pin. The scope is in the high-resolution acquisition mode. There is a very short period of quiet time (no modulation) followed by approximately 12 milliseconds of modem synchronization time (sync time).
SECTION 2: FACTORY TEST PROCEDURE The plot in Figure 2-4 is the same as before but now the scope is in the peak detect acquisition mode. After the mobile radio detects a step response in the RSSI (caused by a down-link transmission), the radio's microcontroller waits an amount of time equal to the programmed value of the "carrier detect delay time" then instructs the modem to look for frame sync.
SECTION 3: FCC LABEL IPM4 Data Transceiver FCC Label Placement 400 – 512 MHz DIVERSITY MOBILE DATA FCC ID : M17-IPM4547 Serial No. Model: IPM4 IPM4 Data Transceiver FCC Label MUST BE SUITABLE FOR TYPING. 400-512MHz DIVERSITY MOBILE DATA RADIO Serial No. Model: IPM4 U.S. PATENT Nos. 5.640.695, 6,018,647, 6,243,393 Made in U.S.A. 400-512MHz DIVERSITY MOBILE DATA RADIO Serial No. Model: IPM4 IPM4-FCCRpt.doc U.S. PATENT Nos. 5.640.695, 6,018,647, 6,243,393 Made in U.S.A.
APPENDIX A: CIRCUIT BOARD DIAGRAMS IPM4 Mobile Radio Digital Circuit Board + + + + + + + IPM4 Mobile Radio RF Circuit Board + + + + + + + + + + + + IPM4-FCCRpt.
APPENDIX B: IPM4 TEST DATA SHEET Program and Configure Radio Date Serial Number Firmware Revision Tester Adjustment / Alignment Procedures Receiver Injection Parameter Spec Injection Frequency Error at RXINJ1(within +/- 100 Hz of exact injection frequency) U34 pin 4 power level Measured +/- 100 Hz -3 to -5 dBm Receiver 1& 2 Parameter Spec Audio DC Amplitude (1 kHz Test tone @ 5.0 kHz Deviation) 2.5 VDC +/- 1mV Audio AC Amplitude (1 kHz Test tone @ 5.
APPENDIX B: IPM4 TEST DATA SHEET Transmit Section Parameter Spec Transmit Modulation Deviation (4.9 kHz while transmitting 2000 character test message) 4.9 kHz Transmit Data Quality (While transmitting 2000 character test messages to the base station) 240 > Transmit Frequency Error (Transmitting 2000 character test message) Measured +/- 100Hz Transmit Power Control Caution: Do not to exceed 40-Watts RF output power during this test.
APPENDIX B: IPM4 TEST DATA SHEET Data Quality Parameter Receiver 1 Data Quality (While receiving 500 character “pings” from base station, 100 pings min, no errors allowed, CRC errors enabled) Receiver 2 Data Quality (While receiving 500 character “pings” from base station, 100 pings min, no errors allowed, CRC errors enabled) Spec Measured 240> 240> Final Tests Uplink Final Parameter Transmit Frequency Error Transmit Modulation Deviation Spec Measured +/- 100 Hz (Transmitting 19, 2000 character test
APPENDIX B: IPM4 TEST DATA SHEET Downlink Final Parameter Spec Measured Downlink Hardware Timing Verification Sync start (RSSI to CS first going low) Recovered Modulation Levels Frame Sync (From end of Sync to CS second time going low) Receiver 1 Data Quality (While receiving 500 character "pings" from base station, 100 pings min, no errors allowed, CRC errors enabled) LED Receiver 1 Receiver 2 Data Quality (While receiving 500 character "pings" from base station, 100 pings min, no errors allowed, CRC