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- Q:I have an ID-12HE reader but I do not understand the output data.
- A: The HID card uses 3 blocks of 32bits in the card. That is 96 bits. It is important to understand that the bits in the card do not directly equal customer bits.
In a normal HID card 8bits are used as the header (11101000) and that leaves 88bits. Now the remaining 88 bits are used in pairs and are always sent as 01 or 10. An 01 is read as a customer '0' bit and a 10 is read as a customer '1' bit. So we only have 44 'customer bits' which is why I send 22ASCII characters representing the 11 digits.
Internally the bits in the card may be arranged as Wiegand26, wiegand34 and wiegand42 formats. HID also have other formats that the customer can dictate.
The ID12HE sends all the card data, so the customer can retrieve any format that is on the card. If the HID card is a Wiegand26 card the last 26 bits sent are the Wiegand bits. If the card is Wieg34 it is the last 34 bits.
- Q: What is the minimal time between reading two different tags readings??
- A: 130mS is the minimum time between reading 2 different tags.
- Q: I want to use the ID12 reader in a portable application. I see that the ID12 requires 5volts and 30mA. Can I reduce the supply voltage and reduce the current.
- A: No. The ID12 voltage cannot be reduced below 4.5volts because it will reset. Innovations have recently introduced the ID-12uP series specially for low power consumption. It can be set to draw as low as 5uA and uses a 2.7-3.5 volt supply, however the read range is only about 6cm, down from 12cm.?
- Q :My reader is reading tags but the output data is corrupted.
- A: Corrupted data is rarely due to the module sending corrupt data. In fact that has never been known to happen. The usual causes are, incorrectly set output format, taking output from wrong pin and bad wiring.
Incorrectly set Format pin
If the user has set the wrong output format, for example Wiegand when ASCII was required, the module will be sending data that the host does not recognize. It may take the form of lots of ‘F’ characters or ‘0’ characters and have more digits than expected.
Taking output from wrong pin
If an output has been taken from the wrong pin, for example the beeper pin then lots of bogus characters will be received. The output format is determined by the module upon switch-on. Changing the setting after switch on will not change the output format. It will be noted that most ID Innovations modules have complementary ASCII output. For connection to a computer direct via a series protection resistor use pin8, else for connection to a UART use pin9.
Bad wiring can cause lots of mysterious events, especially if the host is external. The usual cause is a broken or open circuit ground line. This may result in long strings of nonsense received by the host. The timing can be such that this happens after a genuine read and it looks very convincing that the reader is sending rubbish.
- Q: I occasionally get a phantom read even when no card is near-by.
- There are two main causes of phantom reads. False signals is coming from another nearby RFID reader, there is interference that mimics a card.
False signals is coming from another nearby RFID reader The output data looks correct and the same card, or a combination of cards spaced periodically appear as reads but no card is anywhere near the reader. This can happen if there is another RFID reader in the vicinity, its called cross-talk. What happens is a card has been presented to the remote reader and has been left in the readers RF field. In such a situation the card modulates this readers RF field strongly. The RF field can travel meters or more and is picked up by the second reader and the signal is indistinguishable from a genuine card. In fact it is a genuine card but the signal is sent by a different reader.
The solution is to ensure that readers are not placed in the same area. ID Innovations make crosstalk resistant readers using special techniques for applications such as car parks, however there is no guarantee that they will be free from problems if a 3rd party reader is used nearby. If cross-talk resistant readers are not used in the same locality then they may be made secure by orienting them at 90 degrees to each other to null the fields. Small reader modules are relatively free from crosstalk if they are placed a meter or more apart. Large long range readers will require up to 10meters or more. ID Innovations long range readers (ID125) are designed for car parks and can operate as close as 1meter apart.
Interference that mimics a card A strong RF signal or a harmonic that is close to 125Khz can produce beats (f1-f2) that perfectly mimic genuine card data. ID-Innovations readers have smart software and analyze suspicious signals up to 6 times to eliminate fake reads, however, if the interference is ever present and strong enough, phantom reads can occur. Try not to site readers closer than 1meter apart unless they have special cross-talk features like the ID125. If switching power supplies are used make sure that the switching frequency or its harmonics are well away from 125Khz. See answers for low range.
- Q: I would like to use the ID-20 and ID-12 modules in combination with a PCB that has an RS-232 port. The problem is the modules output TTL level. I have read your documentation about pseudo RS-232 mode, just using a 1k resistor. Could you tell me if this is a reliable solution?
- A: If there are high levels of interference or the cables are long I would not recommend using pseudo RS232 mode, however, for short connections with no interference it should be OK. In my 10 years with Innovations I have never had a single instance of a customer saying there was a problem. Having said that, a MAX232 chip is quite cheap and if there is any doubt I would put one on my PCB.
Certainly for testing the pseudo 232 method will indicate immediately that your system is working. May I suggest you test it with a 'Bray Terminal' that you can download from Google pages.
- Q: My tag is permanently in the reading zone. What delay is between two successfully readings? Does the module send data permanently without any delay?
- A: The standard version ID-2/12/20 read the card only once even if the tag stays in the reading zone permanently, however, there are 3 options for you to control the reader:
a) Some customers use the reset pin (Pin2) and reset the reader so it reads the tag again, the minimum time is 0.333 Second.
b) Pin6 is a ‘Tag in range’ logic output. It goes high for the period the tag is in read range.
Customers can also special version reader which can read tag continuously until the tag going out of the reading zone. The minimum time between 2 readings is 0.3s. This module can be supplied based on an MOQ.
- Q: I am using the reset function to read however it sometimes does not read the card.?
- A: Perhaps the start up after a reset is a bit slow for your UART software. Your UART may be reading rubbish as the module outputs settle after the reset. Once a UART has made an initial error it may need a break in transmission to recover, or even the good data that follows can be read as rubbish. Can you try the following and see if it helps please.
1) Reset as before.
2) Delay the interrogation of the UART by say 100mS, after the reset. If the UART is interrupt driven, disable the UART either or globally or by BSF INTCON,GIE.
3) Clear the UART buffers and any error register because the UART may have been fooled by the rising/falling edges during the reset cycle.
4) Start normal UART interrogation, re-enable interrupts if they are used for the UART.
I strongly suspect this is the main issue, however failing everything else we will look at your application free of charge if you care to send it to our laboratory. You pay for the shipping. If you are not totally dissuaded by your current problems with the LA series, you may be interested to know that we are introducing a new series of reader modules, the ID-12uP, that in ‘slow response’ mode draw only 5uA @ 3v and in ‘fast response’ mode draw 110uA@3v. The range is about 1/3 normal, however if a card is left in read-range, the data is sent continuously. Even lower power is possible at 2.6volt 2.9V. The ID-12uP series are mostly compatible with the ID-12 and ID-12LA” This may be ideal for your application. You can select response times of 250mS, 750mS, 2seconds and six seconds. So with a card left in read range in the 750mS mode will send the data every 750mS and draw 50uA, in 2second response mode it will send the data every second regardless and will draw less than 15uA. In the 6second mode it will send the data every 6seconds and draw just 5uA!!!
- Q: I'm trying to use your ID-20 reader in an RFID pet door project. It seems that I need quite a bit more range so I am about to embark on building an external antenna. My question is, how do I disable the internal antenna in the ID-20, or, if plan to use an external antenna, should I get a reader without the internal?
- A: You may not add an external antenna for an ID-20. If you want to use an external antenna, you need to order the model ID-3LA or ID-2 which have no internal antenna and are specifically made for external antennas applications.
- Q: Reference of ID-3LA RF output voltage. I am using the ID-3LA at 190voltsPKPK. Is this ok?
- The RF output voltage of the ID3LA depends a lot on the antenna. Can you tell me what changes you have experienced?
- Q: Does the sensitivity ( read distance ) of the ID-12LA change with supply voltage from 2.8V - 5V ?
- If the read range of an ID-12LA at 5v with a specific tag is say 10cm then at 2.8v expect around 7cm read range. In these circumstances the range will be determined by the point at which the card first excites (starts working). If there is electrical interference from any source then the range may not be a simple function of card excitation.”
- Q: What is the decoding procedure for ID-3/12/20LA-ISO ? When I read the part, it returns me "\x02 15 D4 B2 28 11 7C 00 41 17 48 00 00 00\r\n" in ASCII tag,
but my national ID number is "34700340136" (decimal)
- Please see method below.
Remove the 02 (STX) from the start and the CR LF and Your Tag data
= 15 D4 B2 28 11 7C 00 41 17 48 00 00 00 0
The National ID is contained in the first 38 bits so get first 38 bits.
FIRST THIRTY EIGHT BITS
00=0 1000=8 0001=1 0100=4 0100=4 1101=D 0010=2 1011=B 1010=A 1000=8
Convert HEX 08144D2BA8 to DECIMAL = 34700340136