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7 Communications Transmission and Communications
Remote
7.1 General
Digital communications is available not only between LT8 controllers and personal computers but also
between a LT8 controller and other LT8 controllers (LT8 controller and other CHINO’s controllers).
These functions are called “Communications Transmission” and “Communications Remote”.
By programming a LT8 controller to Communication Transmission as a master unit and other LT8
controllers to Communications Remote as slave units, the SV of the slave unit (up to 31 sets) can be
programmed through communications. This function can be utilized for using multiple LT8 controllers
in the same condition. The master or slave designation of the LT8 controllers can be programmed by
key operation.
When the communications function of the Mode 6 is programmed
to “trS (Private protocol)” or “trS.2 (MODBUS)”, LT8 controller is
programmed as a master unit (Communications Transmission).
When the communications function of the Mode 6 is programmed
to “rEM (in case a master LT8 controller is programmed to “trS”)”or
“CoM (in case a master LT8 controller is programmed to “trS.2”)”,
LT8 controller is programmed as a slave unit (Communications
Remote).
[Communications Functions Programs and Details of Transmission Data]
Mode 6, Communications
Functions Programming
(Master)
→
(Slave)
Details of Transmission Data
(trS. 2)
→
(CoM)
［
LT8
］
(N.B.) Slave unit has to be
programmed to Key
Lock 3 to receive data.
• Sending (Master) and receiving (Slave) Remote SV data and
Execution SV No. and Run/Ready.
• MODBUS protocol
7.2 Communications Specifications
* Communication system
: Start-stop synchronization system
* Transmission speed
: 19200, 9600 bps (selectable)
* Start bit
: 1 bit
* Data length
: 7bits (ASCII mode) or 8 bits (RTU mode / ASCII mode)
* Parity bit
: Even or Odd or None
* Stop bit
: 1 bit or 2 bit
* Character code
: ASCII (ASCII mode) or Binary (RTU mode)
* Error check
: CRC-16 or LRC (depending on transmission mode)
* Signals in use
: Sending and receiving data only (no control signal in use)
