Company Logo

• 목록
• 게시판 리스트 옵션
  • 수정
  • 삭제

A typical RS485 network can operate properly in the presence of reasonable ground differential voltages, withstand driver contentious situations, provide reliable communications in electrically noisy environments (good common mode rejection using twisted pair cable, shielding provides additional protection), and support thirty-two or more (many IC manufacturers have 1/2, 1/4, 1/8 unit load devices) drivers and receivers on the line. In addition there is no good way to add terminations resistors at the ends of a "star" network. The next thing I tried, in my parade of imperfect solutions, was to add DC biasing resistors (as per the excellent Circuit Cellar articles) and watch the effect on scope traces. If you use an RS485 connection cable or an RS422 connection cable that is longer than 50m, you should add a terminating resistor of approx. The vast majority of C/MRI outputs make use of standard current-sinking, where the transistor switch, built within every C/MRI output line, completes a connection to ground to activate the connected railroad device.

You also avoid the need of an oscilloscope to check for the direction of data flow and the possibility of device failure causing bus contention whereby data tries to flow in both directions simultaneously on the same pair of wires. RS422 is a full-duplex system, meaning that a device using RS422 can send and receive information simultaneously. Connections between the SMINI and the railroad are made using Molex-style right-angle header connectors. The left header connects with the cable running back toward the computer and the right header connects with the cable running to the next node. When using RS232, the serial connections between the computer and SMINI are made using the 3-pin header along the top right edge of the card. You may be wondering, what can I do with serial communications, RS485 standard especially RS485. It can also emulate analog voltage outputs from a variety of other vacuum transducers. The ultra-compact volume of these low-cost DC DC converter modules with high isolation voltage are ideal solutions for industrial electronics, telecom and instrumentation applications, etc. A wide operating temperature range of -40°C to 85°C, even up to 105°C or 125°C, also makes them fit the automotive industry.

However the advantages of RS422, and even more importantly RS485 make their application important to the C/MRI. Although the C/MRI does not have a requirement for two-way simultaneous communication, there are definite advantages to its using a separate wire pair for sending and receiving data - namely reduced design complexity and easier system debug. When comparing RS-485 with Ethernet both of them have advantages and disadvantages. These connectors, used on all previous C/MRI board designs, have proven to be extremely rugged, dependable and cost effective. The capacitor should have enough capacity to absorb the energy, that can be loaded onto the TML during the "propagation round-trip time". Tried and tested in tough automotive exhaust systems at temperatures up to 12,00°C, the KYOCERA AVX high-temperature sensors (HTS) have been made adaptable for various industrial, test lab and smart home applications. Test (booth 1-426) taking place from 11 to 13 June in Nuremberg, Germany. Perhaps one more touch is appropriate: AC-only coupling of the common-mode termination ("DC decoupling" ;-). The Click board™ is equipped with a jumper that can be used to route the termination resistor of 120Ω between the bus lines.

RS485 must be connected like A-A B-B, the 120ohm resistor is not connected by default. However, the model railroad environment can create a lot of electrical noise, especially when using high-frequency power-pulse systems like DCC. Most protocols, like J1708, use a pseudo random generator based on your address to calculate a retry delay, which prevents the same two modules from constantly colliding. I find it easiest to think of the SMINI card as being four cards combined into one, an SUSIC combined with two 24-bit output cards and one 24-bit input card. The SMINI includes circuitry for two 24-pin output cards and one 24-pin input card. It is generally used between one transmitter receiver pair to ONLY one other transmitter receiver pair but each output can drive up to 10 receivers. RS232 is limited to one receiver and one transmitter. If the difference is positive by more than 200mV, the receiver reads a Mark; if the difference is negative by more than 200mV, the receiver reads a Space. The difference between the voltages on the two wires signals a Mark or a Space. RS422 grounding requirements are much less critical since local ground potential does not affect the Mark or Space signals.