SIC24 - Signal & Indicator Controller
Tips for Successful Operation
1. The SIC24 requires a regulated 12 volts DC power supply. Most analog 'Power Packs' will NOT work because they do not provide smooth (filtered) DC power. Also SIC24s may not work correctly with switching power supplies.
2. The power supply must be isolated from the system ground. That is, it can not have one of it's outputs connected to ground (booster ground, loconet ground, house wiring ground, etc). Some wall transformers have a ground connection. Three prongs into the wall suggests the negative output of the power supply is grounded.
3. When multiple SIC24s are used they can be all connected to one power supply. The power supply must be able to supply the current for all the SIC24s. The plus and minus of the power supply must be connected to the same power input terminal on each SIC24.
4. If you have not cut the termination resistor at described in in the Serial Bus section of the manual, the SIC24 will operate without being connected to the bus (Loconet). Operating a SIC24 in this way may be helpful in isolating problems.
5. Be sure the LED current limiting resistors are not less the 470 ohms. This is a general guide line for a typical LED. LEDs operate with varying currents and voltages. If you have a special LED you will need to know it's characteristics in order to use it with a SIC24. You should limit the current of any single SIC24 output to 20 mA and the total of any connector group of eight outputs to 50 mA.
Note: Attempting to turn on all eight LEDs at 10 mA at the same time from a connector group will exceed the rating. However, typically in signaling and most SIC24 applications all eight outputs would not be turned on at the same time. If you require more than five LEDs to be on per connector group than you will have to reduce the LED current.
6. When multiple SIC24s are used be sure to power up all the SIC24 boards at once. A SIC24 requires bus (Loconet) messages to know what it should do. If a required message is not received for some reason, the SIC24 will not work as expected. For example if the state message of another device is sent before the SIC24 is powered up it will miss the message and not respond correctly even though the message was sent.
7. When multiple SIC24s are used there is a lot of bus (loconet) traffic at power on. If possible power up the SIC24s first and then wait 10 seconds or more to turn on other devices and track power. The SIC24 delays at least 4 seconds after power on to start sending messages. Some SIC24s delay longer because the delay time is a function of the base address. Also, the time to stabilize the signals can be long because of all the messages that are present at power on.
8. You can alternately flash all the outputs by programming CV3 with a value of 3. This can be used to test output LED connections.
9. In some cases, attempting to reset all the CVs to the factory default value or clear all CVs above nine using the programming track does not work. This is due to the fact that some systems do not keep voltage on the programming track long enough for the SIC24 to complete the programming of all the 200+ CVs.
10. CV1 is the same as the loco two digit address. Some throttles like the Digitrax DT300 will not allow that CV to be programmed higher than 127. In some cases it is desirerable to program CV1 to greater than 127. There are several ways around this for the Digitrax user.
Note: The SIC24AD CV1 has a different function.
1. If you have access to a DT100 throttle, you can use it.
2. If you have access to a Zerphyr, you can use it.
3. Use addresses starting above 255 by using CV9.
4. Use DecoderPro