The GD-04 “David” GSM communicator User manual The GD-04 module got its name from David, a biblical king who outsmarted Goliath, a giant. In our case, Goliath is meant to be the GSM network. We hope that the skills of your tiny David will help you manage the giant. 1. Basic description GSM antenna Tabs SIM card SIM RESET jumper Bus connector LED indicator Battery connection Output fuses 1.1.
1.2. • • • • • • David can be used as: A switch with SMS remote control. SMS texts for switching particular terminals on/off are configurable. A time-switch which can be activated remotely via a mobile phone (the switch-on period is configurable from 1 second to 10 hours). A relay with dialling-in remote control. Up to 50 tel. numbers can be authorized for each relay. Because calls are not answered dialling-in control within GSM is free of charge.
5. Insert the circuit board back to its position. 6. Do the wiring, see below. 4. Wiring 1. Power supply – use the +12V and GND terminals. Any power supply adapter used should provide 12V DC voltage and up to 500mA of current. If an LT-89 mains adapter is used (a recommended option) wire the grey marked conductor to GND. Do not turn the power supply on until all input/output wiring has been done. 12V DC power supply (LT-89 adapter) _ + 2.
All parameters are sufficiently described on the page so that you do not need to use David’s installation or user manual to perform programming. Programming via the web site is free of charge. No user registration is required. Your David’s settings are not stored on the web server. Instead, you can save them as a file in your computer for future use (the file can then be imported to the page). The page does not allow you to retrieve the current settings of your David.
7. David is not case sensitive (does not distinguish between lowercase and UPPERCASE letters). 8. The use of accented characters is not recommended. 9. After an SMS message has been received, David switches off both the X and Y relays. 10. See table 1 for a brief instruction list. 7.
dd hhh pp is the auto-interrogation frequency in days is the minimum acceptable credit balance is the textual position at which the number showing the balance starts in the reply message from the GSM provider Example: If you require at least 50€ of credit balance, and the USSD code used to query the available balance is *104# and you want a weekly interrogation frequency, use the following instruction: PC, CRD, *104*#, 7, 50, 01 If you do not want automatic interrogation, you can program David to report
11.2.1. DTMF relay control Call David’s tel. number. After about 7 seconds, David responds with a beep on the line (this means that the call has been answered) followed by relay X and Y status indication (in this order): 2 short beeps = OFF, 1 long beep = ON. • Enter the DTMF code. A relay switch-on is confirmed by a long beep, a switch-off by two short beeps. • Terminate the call (David automatically terminates the call after 60 seconds).
• • • • responded to by an SMS report about input activation (a connection to GND). Pressing the B button is responded to by an SMS report about input deactivation (a disconnection from GND). For single-button controls (such as the RC-87 or RC-89), pressing the button is responded to by an SMS report about input activation.
temperature is signalled (e.g. 6°C). Sending an SMS instruction for switching relay X or Y off puts the heating back to normal mode (with A or B disconnected from GND). • If input A or B is used for thermostat enrollment, the status SMS report (obtained from David on an SMS request) contains information about the temperature. Example: STATUS:A0,B0,C0,D0,X1,Y0,GSM:70%,TA:25/24C,TB:22/22C where: TA labels data from thermostat A, TB labels data from thermostat B.
12. Specification Power supply Stand-by consumption Max. consumption (during communication) GSM band RF output power A, B, C and D input terminals Output contact rating X1,X2 a Y1,Y2 Resistive load Inductive (capacitive), lamp load Can be operated according to Safety EMC Radio transmissions Environment Dimensions (without antenna) GSM antenna 11 – 13 V DC approx 20 mA 500 mA E-GSM 850 / 900 / 1800 / 1900 MHz 2 W for GSM 850 / 900, 1 W for GSM 1800 / 1900 activated by a connection to GND max.
David’s settings Input’s SMS reports SMS when activated SMS when deactivated Input A Phone numbers SMS when activated SMS when deactivated Input B Phone numbers SMS when activated SMS when deactivated Input C Phone numbers SMS when activated SMS when deactivated Input D Phone numbers Relays operation Relay X Relay Y ON command OFF command Tel. numbers authorized for relay control ON command OFF command Tel.
Table 1 – A brief list of programming SMS instructions Any programming SMS message must start with a valid access code (see 6.3). Example: PC, ARX, heating on, DRX, heating off Instruction Function Factory default Description Relays X and Y operation SMS to switch relay ON ARX, xxx..x SMS to switch relay OFF DRX, xxx..x Relay switch-on period TMX, t..t Telephone numbers authorised for relay control ADX, x..x,x..x Telephone numbers authorised for relay control with a validity limit. LDX, x..
Additional functions xx…x = new access code, 2 to 8 characters Example: NPC, MARTIN27 xxx..x = text, up to 30 characters Example: STS, HOW ARE YOU NOW xxx..x = tel. number. Up to 2 numbers can be set, previously set numbers are erased. Service numbers are used to report faults: POWER FAIL / POWER RECOVERY 1 LINE OK (GSM signal recovery) Other events – see Optional functions. Instruction STN, erases service number(s).
