The differences between I-8000 and I-87K series I/O modules are
Item | i-8000 series | i-87K series |
Microprocessor | No | Yes (8051) |
Communication interface | Parallel bus (Note1) | Serial bus (Note2) |
Communication speed | Fast | Slow |
DI latched function | No | Yes |
Counter input (for digital input module) | No | Yes (100 Hz) |
Power on value | Yes (Note3) | Yes |
Safe value | Yes (Note3) | Yes |
Host watchdog | Yes | Yes |
Module watchdog | No | Yes |
Programmable slew-rate for AO module | No | Yes |
Note:
1.The 8000 series and 87K I/O modules can both be connected into the same i-8000 MCU, for there are two types of buses on i-8000 series main-board. Through the parallel bus, the CPU can communicate with I/O modules very fast. For digital I/O modules, the communication time takes less than 0.012 ms. For analog I/O modules, it depends on the modules. For example, I-8017H’s scan rate is 50K samples per second and I-8024’s throughput is 2100 samples per second.
2.Through the serial bus (RS-485), the communication speed is 115200 bps Maximum. The communication time depends on the command and response length (bytes). Normally, for digital I/O modules, one module takes less then 1 ms; for analog I/O modules, one sample takes less than 2 ms.
3.The hardware design of the I-8000 series I/O modules doesn’t have the power on value and safe value. Running the DCON firmware on the I-8000 MCU, they can have the functions.
8430/8830/8KE4/8KE8 User’s manual, Jan 2005, Version 1.0, 8MS-002-10 ----- 84
