ZTT0030 Hospital TV interface

Transcription

1 ZTT0030 Hospital TV interface Application, Installation and Programming man0046 Hospital TV interface.doc Revision Reason for update Author Date 1.00 Initial release. IR 31:08:2005

2 Contents 2 INTRODUCTION... 3 WHAT S IN THE BOX?... 3 INSTALLATION... 4 CONNECTING TO THE ZTT RJ45 PINOUT... 5 HANDSET CIRCUIT... 5 POWER SUPPLY AND GROUND RETURN ISSUES... 5 DIAGNOSTICS AND FAULTFINDING DOWNLOADING... 7 PROGRAMMING... 9 CREATING A SIMPLE CONTROLLER MORE ADVANCED APPLICATIONS TV and set-top box combination Provisional access HOW TO PROGRAM CONDITIONAL ACCESS MULTI-LEVEL ACCESS... 12

3 3 Introduction This matchbox-sized unit solves the perennial problem of interfacing TVs to combination nurse call and TV handsets in hospitals. The ZTT0030 requires no modification of the TV and can be in-the-field programmed (using Joey editor software) to interface to any TV, either CRT or LCD, that has IR remote control and a headphone socket. This allows different model TVs to be installed with no hardware changes, rewiring or interface hassles. It s particularly valuable for LCD TVs that are usually impractical to modify. It contains an internal amplifier so that sockets on TVs that are intended to drive only earphones can drive the handset s speaker to a satisfactory level. The ZTT0030 may be used with any nurse-call system handset that has individual contact closure circuits for each button. It can be powered from the nurse-call system and may be installed in the ceiling or attached to the back or top of the TV. What s in the box? The ZTT0030 contains: A programmable controller, with IR and RS232 ports A contact closure interface for 5 switches with a common ground An audio amplifier for driving the speaker in the handset An RJ45 socket for connecting to the handset and 12 volts DC. The controller has an annunciator output that is internally coupled to the audio amplifier. As well as providing a key click when a key is pressed (very helpful for the spongy membrane keys used on most handsets) it allows for power-on diagnostic tones. The controller is field programmable via its RS232 port, so that changes of TV or even set-top box and TV combinations can be easily accommodated. (It takes about 2 seconds to download a new file.) It s possible to program the controller to perform predefined channel selection groups (i.e. send sequences of discrete channel numbers rather than channel up-down commands) and to select between these groups based on an RS232 command. Virtually all IR remote protocols are supported. A LED does dual duty as a power indicator and an IR code transmit indicator. The visibility of the latter function is dependent on the duty cycle of the particular IR protocol being sent some protocols will require a practiced eye to detect! The headphone input is mono with a stereo plug that commons the two channels. It s assumed that the TV s headphone outputs have internal series resistance this is common practice. The load presented to the external device s headphone socket is 10, shunted by 100nF for EMC/RFI reasons. Transformer isolation of the headphone input is available as an option. As standard, its ground is common with the ground on the RJ45 connector. The internal amplifier has a gain of 20 and sufficient power to drive the small handset speaker to a suitable level for the application.

4 4 Installation The diagram shows a typical installation of a ZTT0030. To IR receiver To headphone socket Unmodified LCD or CRT TV Getting the best results from the supplied double-sided adhesive. Both the ZTT0030 box and the optical coupler are supplied with a premium, high-bond-strength self-adhesive foam. This makes installation easy but: The surfaces MUST be clean and dry. Grease, oil, wax or fingermarks greatly reduce the adhesive s strength. It s strongly recommended you use an alcohol wipe to clean the surface and allow a minute or so for all alcohol to evaporate before applying the device. Press down firmly. Once applied, maximum bond strength is achieved after a few days. Ensure that no stress is applied to the joint during this time. ZTT0030 Hospital TV interface Programming & RS232 port com m BOX Command Systems P/L Pwr/sending IR output Headphone input 1. CH+ 2. Spkr + 3. Vol volts RJ45 pinout: 5. CH- 6. Common (Gnd) 7. TV On/Off 8. Vol + Existing CAT5 or similar cable Existing Nurse call wallplate Existing bed remote control

5 ZTT Connecting to the ZTT0030 Since there are a number of bed remote control handsets in common use, the following section describes the interface requirements of the ZTT0030. RJ45 pinout To avoid confusion over RJ45 pin numbering, this is the view looking at the socket on the front of the ZTT0030. This order of pins is assumed in all documentation. If you get it wrong, the unit will not work but will usually not be damaged Handset circuit CH+ 1 Spkr 2 Vol v 4 CH- 5 Gnd 6 TV On/Off 7 Vol+ 8 Channel Up Volume Down Channel Down TV On/Off 12 volts + - Speaker Volume Down Power supply and ground return issues In most installations, a common power supply will be used to power a number of units, perhaps extending over several rooms. Typical maximum current demand for each unit is 200mA, depending on volume and audio content. If the supply voltage falls below 7 volts (possibly due to long cables of too small a cross-sectional area), the unit will reset and play a 3- note tune on the speaker. To avoid this, test for voltage drop at the point furthest from the power supply, with all units on maximum volume on the same TV program. Under no circumstances may the supply voltage exceed 16 volts or the internal audio amplifier will be damaged. If using an existing nurse-call system power supply, check for continuity and, if found, potential difference between the antenna system ground and the nurse-call supply ground. This is because many TVs have no galvanic isolation between antenna and headphone output grounds. If a potential difference (AC or DC) is found in the installation, either order the headphone input isolation option or fit a suitable transformer in the headphone output of the TV. Alternatively, use a 12 volt power supply that is isolated from ground.

6 6 Diagnostics and faultfinding. The ZTT0030 contains a number of features to make it easy and quick to locate wiring and handset problems. When the unit is plugged in/powered up, a 3 note tune should be heard (not very loudly) from the speaker in the connected handset. This indicates that the controller has passed its power-on-self-test and that the power supply, audio amplifier and handset speaker are OK. If the tune is heard but there is no audio from the TV, check the headphone socket connection on the TV and its connecting cable. If no tune is heard but the LED on the ZTT0030 lights, check the speaker in the handset and the wiring to it. If there is no tune and the LED is not lit, check the power supply and related wiring. When a TV key on the bed remote handset is pressed, a faint tick noise will be heard in the handset speaker. This indicates that the unit is programmed to respond to that key and that the key is connected. If one or more keys do not make the tick noise, check the wiring to the handset for the keys that do not respond. If you have downloaded a new program, check that all keys are correctly programmed (see the next section). If the tick noise is heard but the TV cannot be controlled, check the positioning of the IR optical coupler. It should be positioned over the TV s remote control receiver port. If you have downloaded a new program, check that all keys are correctly programmed using the correct codeset file for the TV (see the next section). If the unit makes a 6 note tune (a distinctive sequence of falling and rising notes) each time it is powered, the EEPROM is defective. Most likely cause a lightning strike affecting the installation. If the unit beeps continually or intermittently, check the power supply and wiring for a high-resistance connection. This includes the possibility of a bad RJ45 crimp. If wrong functions on the TV are controlled, there are only two possibilities the wiring to the handset keys has been mixed up or the unit is incorrectly programmed.

7 7 Downloading To download an existing file to a ZTT0030 you will need: 3.5mm "stereo" plug The Joey editor software A serial cable A means of powering the unit. The serial cable is a type that is used for most CommBox products, including the Joey from which the ZTT0030 is derived. The cable is wired as shown in the sidebar diagram If this is the first time you have used the Joey DB9 Female plug Editor software on your PC, you will need to select a serial port. Under the File menu, choose Preferences. There may be a delay while the software tries to communicate with the unit. If nothing is connected a comms timeout error message will appear. Cancel the error message and the Preferences dialog will appear. From the Port drop-down, select the physical port you will be using. If you are using a USB to RS232 adaptor, it may appear as COM4 or something similar, depending on the hardware installed in your PC. Serial cable wiring Once you have chosen the correct comms port and connected the ZTT0030, click the Reset button to test the communication. Having correctly chosen the port, you won t need to do this again. Next, click the Download button. You ll see a progress bar and the file will be downloaded to the unit. For simple applications this generally takes 1 or 2 seconds.

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9 9 Programming Use the Joey editor to program the ZTT0030. For the model, choose Joey Micro Portrait. Next, either load an existing file intended for the ZTT0030 or select Edit Graphics and, by loading a white background and using the text tools, create a screen that looks like the one shown here. Assigning the keys in this way (regardless of how they look on the hospital handset) ensures that the correct functions are mapped to the physical control lines that come from the ZTT0030. Creating a simple controller. Most of the time, the functions you see on the keys are what you want to use, i.e. just a simple remote control for the TV. In this case, it s very easy just select Edit Behaviour and double-click on a button to define its function. A flashing green circle will appear and a dialog window will open, allowing you to choose what you want to happen when that button is pressed.

10 10 To add an action to the selected button, choose Add. You can then choose an existing codeset (a file with a set of IR or RS232 codes in it) or load a new one from the library. Once the codeset is loaded, you can choose the code for the button from the list. Next, fill in the commands for the other buttons. You will not need to load the codeset again to do this. Save the file, download to the unit and you re done!

11 11 More advanced applications TV and set-top box combination If you are installing a TV or monitor with a cable set-top box connected, it s possible to control both devices from the bedside handset by splicing a second IR coupler in parallel with the first and using two codesets. However, you need to take care with toggle type IR commands if both devices use these and you cannot obtain discrete IR commands for your device (check the dealer downloads section on our website) then it s recommended you don t send Power commands to the set-top box at all. To make sure the TV/Monitor selects the correct input to receive signals from the set-top box, send an Input Select command after the Power command. It s usually necessary to insert a delay between them. It doesn t matter that the Input Select command is also sent after the TV is off as it will be ignored by the TV. Provisional access For channel selection, using the Channel Up and Channel Down IR commands isn t the only way of selecting channels. For some applications (such as where there are pay-per-view channels) you might want to consider using discrete channel numbers. But how to do this, when there are only up and down buttons on the handset? The answer lies in the use of multiple screens. Remember, this product is based on a touchscreen design. You may not be able to see the screens change, but they are still there and you can have different commands on each screen, with instructions to swap to the next screen when a key is pressed. Here s a simple example that allows just 4 channels to be accessed. The Volume and Power keys are not shown. The numbers shown on the Up and Down keys are the IR codes sent to the TV and the arrows indicate the screen that is selected when each key is pressed. Each screen is named as the channel that would be selected at the time it is current Scrn Scrn Scrn 9 02 Scrn 10 09

12 12 How to program Conditional Access 1. Set the Volume Up, Volume Down and On/Off keys as Hot Keys. To do this, select Hot Keys from the Handset menu and use the arrows to move the 3 keys to the Hot Key list. 2. Create the first screen and use Duplicate this Screen from the Handset menu to make as many copies as you need. Why use Hot Keys? Hot Keys always work the same way regardless of the screen selected and only need to be programmed once. This saves time and minimises errors. 3. Rename each screen to the channel number that will be selected when it s current. 4. Click the Edit Behaviour radio button and edit each screen in turn, setting up the links to other screens as required. This will give you a system in which the channels that the user can access is determined by the programming in the controller. However, you can do even more than this. Multi-Level Access Because the ZTT0030 is based on our small touchscreen range, there is a Feedback function that allows an external RS232 device to set the unit to a known screen. To use this feature to provide multi-level conditional access, you need to build a number of conditional access groups (each with different or extra channel steps) and use the Feedback function to assign the root screen of each group to a variable equate. Custom software can then send a status packet to each ZTT0030 as required. A correctly-formatted status packet will force the unit to the desired screen, allowing the user to perform up-down navigation from this point only. Addressable RS232 connection to each ZTT0030 could be via low-cost Ethernet serial servers. This would allow a web-based pay-per-view system to be established.