What is a null serial cable?
A null modem serial cable (frequently called a crossover cable) is used to connect two DTE devices together without the use of a DCE device in between. For this to happen, the Transmit (TXD) and Receive (RXD) pins on one of the serial connectors are flipped.
How do I know if I have a null modem serial cable?
To tell if your NI serial cable is null modem or straight though, search for its part number in NI Serial Hardware Specifications and Features and note the cable type in the description. Alternatively, you can use a handheld DMM to test continuity on the individual pins of your serial cable.
Is a null modem cable the same as a serial cable?
Null modem cables are serial cables that use an alternative pinout for different functionality. Originally, all serial cables were AT cables and could not connect two devices (such as two computers) directly. They required a modem or similar equipment as a go-between.
Are there different types of RS232 cables?
The RS-232 specification defines two types of serial devices, DTE and DCE. DTE normally refers to the serial port on a PC or terminal, while DCE refers to a modem or other type of communications device.
Are there different types of RS-232 cables?
Does RS-232 cable need to be shielded?
RS-232 serial interface cables should be shielded, low capacitance cables, ideally designed specifically for serial data transmission. The shield should be grounded at both ends of the cable.
Why is RS485 better than RS-232?
RS232 is more than able to perform for a short distance and low data speed requirements. RS232 has a transmission speed of 1Mb/s up to 15M. However, RS485 has a data transmission speed of up to 10Mb/s for a distance of 15M. At the maximum of 1200M, RS485 transmits at 100Kb/s.
How long can you run RS-232 cable?
50 feet
The guidelines established by paragraph 3.1 of the RS-232-C standard recommend limiting the cable length to 50 feet or less. The standard does allow the cable length to exceed 50 feet, provided that its total capacitance is less than 2500 pF. No specific cable construction type is recommended in the EIA specification.
What does Rs stand for in RS-232?
This standard, which was developed by the Electronic Industry Association and the Telecommunications Industry Association (EIA/TIA), is more popularly called simply RS-232, where RS stands for \”recommended standard.