1. Different characteristics
HTL: noise tolerance is relatively large, has a strong anti-interference ability. The disadvantage is that the working speed is relatively low, so it is mostly used in some industrial control equipment that does not require high working speed and high anti-interference capability.
TTL: TTL level signals directly connected to the integrated circuit without the need for expensive line drivers and receiver circuits; computer processor-controlled equipment within the data transfer is carried out at high speed, and the operation of the TTL interface to meet this requirement. TTL-type communication in most cases, is the use of parallel numbers.
2. Voltage is different:
HTL: The threshold voltage is higher. When the supply voltage is 15V, the que voltage reaches 7-8V.
TTL: is utilized the most because usually data representation using binary provisions, +5V is equivalent to logic "1", 0V is equivalent to logic "0".
3. Different transmission distances:
HTL: For HTL encoders with symmetrical du-negative signal output, the signal transmission distance can reach 300 meters.
TTL: For TIL encoders with symmetrical negative signal output, the signal transmission distance can be up to 150 meters.
Introduction of encoders htl and ttl
HTL, which is often referred to as push-pull, is a combination of NPN+PNP, so it supports both PNP and NPN control circuits. Circuit is simple, easy to use, wide operating voltage, encoder commonly used 5 to 30V can be (Note: HTL output signal level is generally equivalent to the operating voltage minus transistor voltage drop). Strong anti-jamming ability, its main disadvantage is that the working speed is relatively low, so it is mostly used in the working speed requirements are not high and the anti-jamming ability of some of the higher requirements of industrial control equipment.
TTL, called long wire drive, some in the form of 5VRS422. Its general operating voltage is 5V, in practice, its use of mutually symmetrical signals such as (A and A inverted), can effectively remove interference signals, so you can achieve long-distance communication and maintain signal quality.
Another TTL circuit response time is short, accordingly its response frequency is very high. Currently RS422 can reach 300KHZ, higher than HTL.
For TTL encoders with symmetrical negative signal output, the signal transmission distance can reach 150 meters.
For HTL encoders with symmetrical negative signal output, the signal transmission distance can be up to 300 meters.