A Secret Weapon For RS485 Standard > 자유게시판

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If you're doing high-speed switching you'll have to give this a lot more thought. If you are interested in how the SMINI works, and in debugging it in case of trouble, I will explain what the SMINI does and give you a tour of its schematic. This is the case for nearly every personal computer, although the RS232 serial port has mostly been phased out of the latest PCs. However for special cases that may arise, it is easy to vary the output configuration to handle the alternative current-sinking case. The situation is exactly reversed when using alternative current-sourcing rather than standard current-sinking. Fig. 4-6 shows a sub-schematic detailing the latch and output transistor portion of the SMINI card, configured for both the standard current-sinking and optional current-sourcing. Fig. 4-2 shows the parts layout for the SMINI card. These resistors are quite large, so this is one of the trickier parts of fitting everything together. Then later, if you find it desirable to add filtering, it is a simple task to cut the trace on the bottom side of the board and insert the desired parts.

Then it pulls line RB0, Pin 33, high to activate, or enable, U9. The RS485 standard defines a balanced two-wire transmission line, which may be shared as a bus line by up to 32 driver/receiver pairs. Such cross-coupling effects become especially prevalent where RS485 cable runs are long and in close parallel proximity to DCC or Railcommand track wiring. The bypass caps are close to their respective power pins and the ESD diodes are snuggled up next to the connectors. The RP2040 has two I2C peripherals but giving up two more of the limited GPIO pins wasn't an option. This transciever is quite nice- its bells and whistles include ESD protection, fail safe, hot swap, and more. To keep things simple, I went with the same transciever IC used in the Lumen motherboard, the MAX3078E. The vacuum sensors I'm using for Starfish are the CFSensor XGZP6857D I2C gage pressure sensors, the same ones used on the latest revision of the Lumen motherboard.

These are used to measure the air pressure in the vacuum lines to determine if a part is on the nozzle. The final piece of the pneumatic system is a pair of vacuum sensors. This combination provides a complete system node with 48 outputs and 24 inputs on a single card. The emulation feature can be used to upgrade and replace other vendors’ gauges in OEM applications without changing system software. The varistors (RV1401, RV1402 protect against coil overvoltage that can be caused by hot plugging or loose connections. However, the model railroad environment can create a lot of electrical noise, especially when using high-frequency power-pulse systems like DCC. These are some incredibly sophisticated and impressive chips, sporting features like 256 microsteps, dynamic current scaling, stall detection, and sensorless homing. This signal is used for sensorless homing- the TMC2209 will pull this signal high when it detects a stall which can be used to detect when the gantry collides with its physical endstop. If you desire more I/O than provided by a single SMINI, you can simply distribute additional SMINI cards around your layout to build up to whatever level of capability you desire.

And, because we are using the more advanced RS485 ICs, we expand our maximum node capability from 16 to 128. Because of this doubling up of the number of RS485 transceiver ICs and the corresponding use of 4-wires, this arrangement is typically referred to throughout the commercial and industrial world as a "Full Duplex" implementation of RS485. In many ways the RS485 standard is similar to RS422. The SMINI and the SUSIC can make use of four interface standards: Universal Serial Bus (USB), RS232, RS422 and a "full duplex" implementation of RS485. RS422 is a full-duplex system, meaning that a device using RS422 can send and receive information simultaneously. Laying out these motor drivers can be very intimiating, but I was able to stick with it and get it working. It doesn't mean you should, but you have a lot of leeway when working with it. The Series 970B have standard 15 pin HD Sub-D connector. We have been producing these converters based on FTDI technology, for over 15 years and have supplied major projects in Civil Engineering, the Military, Aerospace, and Nuclear Industries.