SM220UF1

DATASHEET SM220 Module ©2008-2020 Synapse Wireless, All Rights Reserved. All Synapse products are patent pending. Synapse , the Synapse logo, SNAP, and Portal are all registered trademarks of Synapse Wireless, Inc. Doc# 116-031507-001-G002 6723 Odyssey Drive // Huntsville, AL 35806 // (877) 982-7888 // Synapsewireless.com SNAP Engine SM220 Modules Overview The SNAP Engine Model SM220 series consists of the SM220UF1 part number. It is an IEEE 802.15.4, low-power, highly reliable solution for embedded wireless control and monitoring networks requiring high data rates. It embeds Synapse’s SNAP OS, the industry’s first Internet-enabled, wireless mesh network operating system, into the Atmel ATmega128RFA1 single-chip AVR® microcontroller with an integrated transceiver that delivers up to 2Mbits/sec. This low-cost module can have current consumption under 390nA to better enable battery-driven systems. The SM220 also includes a Skyworks SE2431L front-end module, which provides a power amplifier and LNA for increased range. SNAP’s on-board Python interpreter provides rapid application development and over-the-air programming, while Atmel’s low-power RF single-chip design saves board space and lowers power consumption. The modules provide up to 15 channels of operation in the ISM 2.4GHz frequency band. By default, the SNAP operating system automatically forms a mesh network with other nodes immediately on receiving power. No further configuration is necessary. Multiple unrelated SNAP networks can exist within the same area through several configuration options outlined in the SNAP User Guide available from www.synapsewireless.com. NOTE: Channel 15 is receive-only due to FCC power restrictions. This data sheet covers part number SM220UF1: • 32 GPIO with up to 7 A/D inputs • 128k flash, 58.5k free for over-the-air uploaded user apps • Two UART ports for control or transparent data • Low power modes: • Timed Sleep Mode 1 : 1.27 µA • Timed Sleep Mode 2 : 1.47 µA • Untimed Sleep Mode : < 390 nA • Spread Spectrum (DSSS) technology • Up to 2 Mbps radio data rate • 2.4 GHz RF Frequency • AES 128-bit encryption • Integrated on-board compact F antenna or U.FL connecter • Surface Mount, Solder-able • 4K internal EEPROM 1 • 8 PWM outputs • Supports over the air firmware upgrades. (This process is further defined in the Portal User Guide.) SM220 – Surface Mount Module The SM220 is a surface mount module based on the ATmega128RFA1 chip. All the details appropriate for the chipbased version of ATmega128RFA1 SNAP apply to the SM220, with the following additions and exceptions. Pin numbers below refer to the pad on the SM220 footprint, with is a 64-pin arrangement of eight rows ("A" through "H") by eight columns ("1" - "8"). To reference IO pins in your code, use the SNAPpy IO number from the table below. Form Factor The SM220 is in a surface mount form-factor. The pad arrangement is shown below.  BOTTOM VIEW A1 A2 A3 A4 A5 A6 A7 A8 B1 B2 C1 C2 C3 C4 C5 C6 C7 C8 D1 D2 D3 D4 D5 D6 D7 D8 E1 E2 E3 E4 E5 E6 E7 E8 F1 F2 F3 F4 F5 F6 F7 F8 G1 G2 G3 G4 G5 G6 G7 G8 H1 H2 H3 H4 H5 H6 H7 H8 B3 B4 B5 B6 B7 B8 The pad designators "A1" through "H8" will be used throughout the remainder of this document. 2 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002 Specifications Table 1.1: SM220 Specifications at 23° C and 3.3V unless otherwise noted Performance Outdoor LOS Range 1 mile using u.fl antenna Transmit Power Output up to +20 dBm RF Data Rate 250Kbps, 500Kbps, 1Mbps, 2Mbps Receiver Sensitivity -103 dBm (1% PER, 250Kbps) Supply Voltage 2.0 - 3.6 V Transmit Current (Typ@3.3V) at +20 dBm: 150 mA at +6 dBm: 55 mA Idle/Receive On Power (Typ@3.3V) Requirements Idle/Receive Off (Typ@3.3V) General Networking 22 mA 7.8 mA Sleep Mode Current (Typ@3.3V) Timed Sleep: 1.27 µA Untimed Sleep Mode : 390 nA Frequency ISM 2.4 GHz Spreading Method Direct Sequence (DSSS) Modulation O-QPSK Dimensions 29.8mm x 19mm Operating Temperature - 40 to 85 deg C. Antenna Options U.FL and on-board compact F antenna Weight 3 grams Topology SNAP Error Handling Retries and acknowledgement Number of Channels 15 fully operational channels. To avoid exceeding FCC limits, channel 15 operates in a receive only state. 3 UARTS with optional Available I/O HW Flow Control Agency Approvals 2 Ports GPIO 32 total; 7 can be analog-in with 10bit ADC FCC Part 15.247 FCC ID: U9O-SM220 Industry Canada (IC) 7084A-SM220 SM220 Module Pin Definitions For pin locations, consult the SM220 Mechanical drawing later in this document. Table 1.2: SM220UF1 Pin Assignments SM220 Pin SNAPpy IO Pin Name Pin Description A1 - GND Power Supply A2 - VCC Power Supply A3 - VCC Power Supply A4 24 PF0_ADC0 IO or Analog0 A5 26 PF2_ADC2_DIG2 IO or Analog2 or software SPI CLK A6 28 PF4_ADC4_TCK IO or Analog4 or JTAG Test Clock A7 30 PF6_ADC6_TDO A8 - GND B1 18 PE2_XCK0_AIN0 B2 19 PE3_OC3A_AIN1 B3 21 PE5_OC3C_INT5 IO or UART0 RTS Input or PWM or Interrupt B4 25 PF1_ADC1 IO or Analog1 or software SPI 1 MOSI B5 - B6 29 1 IO or Analog6 or JTAG Test Data Out or software I 2C1 SDA Power Supply IO or software SPI 1 MISO or Analog Comparator or External Clock IO or Analog Comparator or PWM or Output Compare Match Test Point - Do Not Use PF5_ADC5_TMS IO or Analog5 or JTAG Test Mode Select 1 Software generated SPI and I2C functions. 4 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002 SM220 Pin SNAPpy IO Pin Name Pin Description IO or Analog7 or JTAG Test Data In or software I 2C1 B7 31 PF7_ADC7_TDI B8 - GND C1 16 C2 17 PE1_TXD0_PDO IO or UART0 Data Out C3 20 PE4_OC3B_INT4 IO or UART0 CTS Output or PWM or Interrupt C4 22 PE6_T3_INT6 IO or Interrupt C5 23 PE7_ICP3_INT7_CLK0 C6 - NC C7 - NC C8 - NC Test Point - Do not use D1 5 PB5_OC1A_PCINT5 IO or PWM or Interrupt D2 6 PB6_OC1B_PCINT6 IO or PWM or Interrupt D3 7 D4 - NC D5 - NC D6 - NC D7 - NC D8 - GND E1 2 PB2_MOSI_ PCINT2 2 IO or Interrupt E2 3 PB3_MISO_ PCINT32 IO or Interrupt E3 4 PB4_OC2A_PCINT4 IO or PWM or Interrupt E4 - NC E5 - NC SCL Power Supply PE0_RXD0_PDI_ IO or UART0 Data In or Interrupt PCINT8 IO or UART1 RTS input or Clock Output Buffer or Interrupt Test Point - Do not use PB7_OC0A_OC1C_P IO or PWM or Interrupt CINT7 Power Supply 2 These pins have special SPI hardware that is not natively supported by SNAP. You can use PEEK and POKE to initiate and enable this hardware functionality, but it is not supported by Synapse and we cannot guarentee your results. 5 SM220 Pin SNAPpy IO Pin Name Pin Description E6 - NC E7 - NC E8 - NC F1 0 PB0_SSN_PCINT02 IO or Interrupt F2 1 PB1_SCK_PCINT12 IO or Interrupt F3 9 PD1_SDA_INT1 3 IO or Interrupt F4 8 PD0_SCL_INT03 IO or Interrupt F5 - F6 - F7 - NC F8 - GND Power Supply G1 - CLKI (Internal 1K pulldown) G2 15 PD7_T0 IO G3 12 PD4_ICP1 IO or UART1 CTS output or Input Capture G4 10 PD2_RXD1_INT2 IO or UART1 Data In or Interrupt G5 37 PG5_OC0B IO or PWM G6 - NC G7 - NC G8 - GND Power Supply H1 - GND Power Supply H2 14 PD6_T1 IO or Timer/Counter1 clock input H3 13 PD5_XCK1 IO H4 11 PD3_TXD1_INT3 IO or UART1 Data Out or Interrupt H5 - RESET# Module Reset, Active Low H6 - NC Test Point - Do Not Use Test Point - Do Not Use 3 These pins have special I2C hardware that is not natively supported by SNAP. You can use PEEK and POKE to initiate and enable this hardware functionality, but it is not supported by Synapse and we cannot guarentee your results. 6 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002 SM220 Pin SNAPpy IO Pin Name H7 - NC H8 - GND Pin Description Power Supply You must preserve access to UART1 as a serial connection in order to be able to serially update firmware on the node, or to recover the node by forced script removal or parameter reset. As a convenience, here is a cross reference from SM220 pad back to SNAPpy IO. Table 1.3: SM220/SNAPpy IO Cross Reference Electrical Characteristics Unless otherwise specified in this document, all electrical characteristics conform to the Atmel ATmega 128RFA1 microcontroller. Detailed specifications on all electrical characteristics are available on the Atmel website at http://www.atmel.com/ 7 Table 1.4: SM220 DC Characteristics at 25° C Symbol 4 VCC Parameter Condition Min Supply Voltage 2.0 Typ 3.3 Max 3.6 Units V Table 1.5: ADC Electrical Characteristics (Operating) Symbol 5 Parameter VREFH ADC Voltage Reference, High VINDC Analog input voltage Condition Min Typical Programmable 1.5 Single Ended 0 1.8 0 3.3 Differential 6 1.6 Max 1.8 Unit V V Mechanical Drawings SM220UF1 Mechanical Drawing on page 9 and Block diagram showing the major subsystems comprising Model SM220 on page 10 show the modules with the compact F antenna ad U.FL Connector options. NOTE: The area under and around the module’s antenna (marked KEEP OUT AREA and tinted red) should have no components and no copper on any layer of the printed circuit board. Additionally, leave enough clearance around the module for worst case component and processing variances. For best performance, the module should be mounted on the outside edge of the circuit board with the antenna side as close to the edge of the board as possible. 4 Absolute maximum stress rated voltage for VCC is -0.3 to 3.6. It is recommended that bulk capacitance be located as close as possible to the VCC pin on the host board. Ideally, use a single 47µF capacitor rated at 10V directly at the VCC pin. 5 VREFH is programmable to three fixed values; 1.5V, 1.6V, and 1.8V. The VREFH value will be 1.6 volts if you do not explicitly adjust it by poking the ATmega128RFA1 registers. 6 Each differential analog input may be as high as 3.3V but the single-ended voltage is still limited to the voltage reference. 8 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002 Figure 1.1: SM220UF1 Mechanical Drawing 9 Figure 1.2: Block diagram showing the major subsystems comprising Model SM220 Selecting an Antenna The SM220 uses the on-board compact F antenna by default. If you wish to use an external U.FL antenna with your application, you will need to set bit 0x0010 of NV ID 64 to 1. This is a one-time change that will persist through reboots and program changes. To revert to the on-board antenna, change bit 0x0010 of NV ID 64 back to 0. Antenna Gain Performance NOTE: Antenna gain performance information is based on information from the individual companies at the time this document's release. For added assurance, it's best to obtain antenna performance information directly from that antenna's manufacturer. 10 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002 HyperLink Technologies HG2405RD-RSP Figure 1.3: HyperLink Technologies HG2405RD-RSP Antenna Gain Performance Pulse W1027 Figure 1.4: Pulse W1027 Antenna Gain Performance 11 ANT-2.4-CW-RAH-RPS Figure 1.5: ANT-2.4-CW-RAH-RPS Antenna Gains Performance ANT-OSC-8.0-1 Figure 1.6: ANT-OSC-8.0-1 Antenna Gains Performance 12 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002 Board Mounting Considerations Processing Table 1.6: Recommended Reflow Profile Parameter Value Ramp up rate (from Tsoakmax to Tpeak) 3º/sec max Minimum Soak Temperature 150ºC Maximum Soak Temperature 200ºC Soak Time 60-120 sec TLiquidus 217ºC Time above TL 30-60 sec (recommended: 40 sec) Tpeak 230º - 250ºC (recommended: 235ºC) Time within 5º of Tpeak 20-30 sec Time from 25º to Tpeak 8 min max Ramp down rate 6ºC/sec max Figure 1.7: Reflow Profile Graph 13 Pb-Free Soldering Paste Use of “No Clean” soldering paste is strongly recommended, as it does not require cleaning after the soldering process. Cleaning In general, cleaning the populated modules is strongly discouraged. Residuals under the module cannot be easily removed with any cleaning process. • Cleaning with water can lead to capillary effects where water is absorbed into the gap between the host board and the module. The combination of soldering flux residuals and encapsulated water could lead to short circuits between neighboring pads. Water could also damage any stickers or labels. • Cleaning with alcohol or a similar organic solvent will likely flood soldering flux residuals into the two housings, which is not accessible for post-washing inspection. The solvent could also damage any stickers or labels. • Ultrasonic cleaning could damage the module permanently. The recommended approach is to consider using a “no clean” soldering paste and eliminate the post-soldering cleaning step. Repeating Reflow Soldering Only a single reflow soldering process is encouraged for host boards. Rework The Model SM220 Module can be unsoldered from the host board, but the process is likely to damage the chip and not recommended. If attempting this, use of a hot air rework tool and hot plate for pre-heating from underneath is recommended. Avoid overheating. WARNING: Never attempt a rework on the module itself (e.g. replacing individual components). Such actions will terminate warranty coverage. Additional Grounding Attempts to improve module or system grounding by soldering braids, wires, or cables onto the module RF shield cover is done at the customer's own risk. The numerous ground pins at the module perimeter should be sufficient for optimum immunity to external RF interference. 14 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002 Packaging Synapse SM series modules are available on plastic reels of carrier tape. The dimensions for those reels are provided below. H+/-0.5 C1+/-1.0 A+/-0.2 C+0.5 -0.2 T+/-0.3 B+/-0.2 D+/-2.0 44.5 ø330 2.20 13.0 2.20 10.75 99.5 All dimensions are in mm. 1. 2. 3. 4. 5. 6. Sprocket hole pitch cumulative tolerance: +/-0.2mm. Carrier camber not to exceed 1mm in 250mm. All dimensions meet EIA-481-C requirements. Thickness: 0.35mm +/- 0.05mm. Packing length per reel: 12.6 meters. Component load per reel: 500 pieces. 15 Agency Certifications United States (FCC) The Model SM220 modules comply with Part 15 of the FCC rules and regulations. Compliance with the labeling requirements, FCC notices, and antenna usage guidelines is required. In order to comply with FCC Certification requirements, the Original Equipment Manufacturer (OEM) must fulfill the following requirements. 1. The system integrator must place an exterior label on the outside of the final product housing the SM220 Modules. FCC Label on page 16 below shows the contents that must be included on this label. 2. SM220 Modules may only be used with the antenna that has been tested and approved for use with the module. Please refer to the antenna table provided in this section. OEM Labeling Requirements NOTICE: The OEM must make sure that FCC labeling requirements are met. This includes a clearly visible exterior label on the outside of the final product housing that displays the contents shown in FCC Label on page 16 below. MANUFACTURERSNAME BRANDNAME or TRADENAME Contains SM220 FCC ID: U9O-SM220 This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interferences, and (2) this device must accept any interference received, including interference that may cause undesired operation. Figure 1.8: FCC Label FCC Notices WARNING: The SM220 modules have been tested by the FCC for use with other products without further certification (as per FCC Section 2.1091). Changes or modifications to this device not expressly approved by Synapse Wireless Inc. could void the user’s authority to operate the equipment. NOTICE:  OEM’s must certify final end product to comply with unintentional radiators (FCC Sections 15.107 and 15.109) before declaring compliance of their final product to Part 15 of the FCC Rules. NOTICE: The SM220 modules have been certified for remote and base radio applications. If the module will be used for portable applications as defined by the FCC, the device must undergo SAR testing. NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed 16 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002 and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: • Reorient or relocate the receiving antenna. • Increase the separation between the equipment and receiver. • Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. • Consult the dealer or an experienced radio/TV technician for help. This device complies with Industry Canada licence-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device. Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes : (1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le fonctionnement. FCC Approved Antennas The SM220 modules are FCC-approved for fixed base station and mobile applications. Notice:  To reduce potential radio interference to other users, the antenna type and its gain should be chosen so that the equivalent isotropically radiated power (EIRP) is not more than that permitted for successful communication. This module has been designed to operate with the antennas listed in SM220 Approved FCC Antenna on page 17 and SM220 Approved FCC Antennas on page 17 below. The required antenna impedance is 50 ohms. Table 1.7: SM220 Approved FCC Antenna Part Number Compact F Antenna Type PC Board Trace Antenna Gain Impedance 0.0 dBi 50Ω Application Fixed/Mobile Min. Separation 20 cm. Table 1.8: SM220 Approved FCC Antennas Part Number Pulse W1027 Type Dipole (quarterwave RPSMA) HyperLink HG2405RD- Dipole (quarterRSP wave RPSMA) ANT-OSC-8.0-1 Whip (RPSMA) Gain Impedance Application Min. Separation 3.2 dBi 50Ω Fixed/Mobile 20 cm. 5.5 dBi 50Ω Fixed/Mobile 20 cm. 8 dBI Fixed/Mobile 20 cm. 50Ω 17 Part Number Type Gain Impedance Application Min. Separation Helical Whip ANT-2.4-CW-RAH-RPS (quarter-wave 1.6 dBI 50Ω Fixed/Mobile 20 cm. Fixed/Mobile 20 cm. RPSMA) Helical Whip ANT-2.4-CW-RH-RPS (quarter-wave RPSMA) -0.9 dBi 50Ω For more information on approved antennas, please consult the manufacturer’s website. WARNING: RF Exposure: This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with minimum distance 20 cm between the radiator and your body. This transmitter must not be co-located or operating in conjunction with any other antenna or transmitter. NOTICE: The preceding statement must be included as a CAUTION statement in OEM product manuals in order to alert users of FCC RF exposure compliance. NOTE: Antenna and transmitters may be co-located or operated in conjunction with this device only if the transmitters do not simultaneously transmit. Otherwise, additional regulatory requirements will apply. Canada (IC) This device complies with Industry Canada license-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device. Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes : (1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le fonctionnement. Under Industry Canada regulations, this radio transmitter may only operate using an antenna of a type and maximum (or lesser) gain approved for the transmitter by Industry Canada. To reduce potential radio interference to other users, the antenna type and its gain should be so chosen that the equivalent isotropically radiated power (EIRP) is not more than that necessary for successful communication. Conformément à la réglementation d'Industrie Canada, le présent émetteur radio peut fonctionner avec une antenne d'un type et d'un gain maximal (ou inférieur) approuvé pour l'émetteur par Industrie Canada. Dans le but de réduire les risques de brouillage radioélectrique à l'intention des autres utilisateurs, il faut choisir le type d'antenne et son gain de sorte que la puissance isotrope rayonnée équivalente (p.i.r.e.) ne dépasse pas l'intensité nécessaire à l'établissement d'une communication satisfaisante. 18 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002 This radio transmitter Model: SM220, IC: 7084A-SM220 has been approved by Industry Canada to operate with the antenna types listed below with the maximum permissible gain and required antenna impedance for each antenna type indicated. Antenna types not included in this list, having a gain greater than the maximum gain indicated for that type, are strictly prohibited for use with this device. Le présent émetteur radio Model : SM220, IC : 7084A-SM220 a été approuvé par Industrie Canada pour fonctionner avec les types d'antenne énumérés ci-dessous et ayant un gain admissible maximal et l'impédance requise pour chaque type d'antenne. Les types d'antenne non inclus dans cette liste, ou dont le gain est supérieur au gain maximal indiqué, sont strictement interdits pour l'exploitation de l'émetteur. Table 1.9: SM220 Approved IC Antenna Part Number Compact F Antenna Type PC Board Trace Antenna Gain 0.0 dBi Application Fixed/Mobile Min. Separation 20 cm. Table 1.10: SM220 Approved IC Antennas Part Number Pulse W1027 HyperLink HG2405RDRSP ANT-OSC-8.0-1 ANT-2.4-CW-RAH-RPS ANT-2.4-CW-RH-RPS Type Gain Application Min. Separation Dipole (quarter-wave RPSMA) 3.2 dBi Fixed/Mobile 20 cm. Dipole (quarter-wave RPSMA) 5.5 dBi Fixed/Mobile 20 cm. Whip (RPSMA) 8 dBI Fixed/Mobile 20 cm. 1.6 dBI Fixed/Mobile 20 cm. Helical Whip (quarter-wave RPSMA) Helical Whip (quarter-wave -0.9 RPSMA) dBi Fixed/Mobile 20 cm. IC OEM Labeling Requirements Labeling requirements for Industry Canada are similar to those of the FCC. A clearly visible label on the outside of the final product housing must display the contents shown in IC Label on page 19 below. MANUFACTURERSNAME BRANDNAME or TRADENAME MODEL: Contains SM220 IC: 7084A-SM220 Figure 1.9: IC Label 19 NOTE: The OEM can choose to implement a single label combined for both FCC and IC labeling requirements. If a combined single label is chosen, there must be a clearly visible label on the outside of the final product housing displaying the contents shown in Combined FCC and IC Label on page 20 below. MANUFACTURERSNAME BRANDNAME or TRADENAME Contains SM220 FCC ID: U9O-SM220 Contains SM220 IC: 7084A-SM220 This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interferences, and (2) this device must accept any interference received, including interference that may cause undesired operation. Figure 1.10: Combined FCC and IC Label ESD Warnings NOTE: The SM220UF1 modules are ESD sensitive devices. During your manufacturing or assembly process, it is critical to have good ESD controls in place when handling the device or connecting an external antenna to the u.FL connector. During field installation process, Synapse recommends the following practices when connecting an antenna or cable to the RP-SMA bulkhead: NEEDED MATERIALS · 50 OHM Terminator plug RP-SMA: Part Number 132360RP from Amphenol ATTACHING THE TERMINATOR TO THE BULKHEAD Make sure the power is off. Attach the 50 OHM Terminator to the RP-SMA bulkhead hand tight. Keep the 50 OHM Terminator on the bulkhead at all times, until the antenna replaces the 50 OHM Terminator. When installing the device, the technician must be grounded with a proper ground strap. ATTACHING THE ANTENNA When it is time to attach the antenna, touch a grounded surface, remove the 50 OHM Terminator and screw on the antenna tightly. Tighten a 1/4 turn with a pair of needle nose pliers. Do not overtighten or the RF pin in the bulkhead will crack, creating poor RF link quality. 20 SNAP Engine SM220 Series Data Sheet — 116-031507-001-G002