−3−
3
COMMUNICATIONS SPECIFICATIONS
* Communication system: Half-duplex start-stop synchronization (polling selecting system)
* Protocol: MODBUS protocol
* Transmission speed: 19200, 9600 bps selectable
* Start bit: 1 bit
* Data length: 7 bits (ASCII)/8 bits (RUT/ASCII) selectable
* Parity bit: Even / Odd / Disabled selectable
* Stop bit: 1 bit / 2 bits selectable
* Transmission code: Binary (RTU) / ASCII (ASCII) (depending on protocol)
* Error check: LRC (ASCII)/CRC-16 (RTU) Depending on protocol
* Data transmission procedure: None
* Signals in use: Transmitted and received data only (no control signal in use)
4
SETTING OF COMMUNICATIONS
PARAMETERS
Follow the flow chart and set up 5 items such as “Protocol”, “Communications function”, “Instrument
No.”, “Transmission speed” and “Character”.
(Operation screen)
Mode.1
Mode.6
Remote
／
Local
Digital
transmission
Remote shift
Protocol
Press 2 seconds at any screen to go back to “mode 6”.
Character
Transmission
speed
Instrument
No.
function
When you set the parameter (writing), set the key lock at first.
LT830 controller is always ready for communication. It responds at anytime to data requests from the
personal computer. However, when you set the parameter or control the instrument from the personal
computer, you need to set key lock (lock 3) on LT830 at first. Key lock will be set at the front key on
LT830 or through personal computer communication. If you try to set the parameter or operate
instrument from the personal computer at Non-lock, Lock1, Lock 2 LT830 will show error code 12H.
（
See paragraph 6.6
）
5times
2seconds
4times
