Instruction manual

3-20 5. Universal Serial Communications
5. Universal Serial
Communications
Universal Serial Communications
• A general purpose computer or an ASCII unit of the PLC (master station) controls the
ZM-300 series (slave station) using dedicated commands.
• The ZM-300 series internal user memory addresses ($u) must be used for memory
allocation for switch, lamp or data display parts. When the master station specifies a
screen number, data is written to the internal memory address ($u) allocated for the
screen. If the screen is switched internally, the new screen number is read and is
written to the internal memory address ($u) allocated for the screen.
• For 1 : 1 connection, the ZM-300 series can send an interrupt to the master station
through switch activation, write command from the keypad, and screen change.
• Use CN1 of the ZM-300 series for connection with a general-purpose computer. Either
signal level RS-232C or RS-422 (RS-485) can be selected.
• In addition to 1 : 1 connection, 1 : n connection is available between the
general-purpose computer and the ZM-300 series via RS-422. (A maximum of 32
ZM-300 series can be connected.) For 1 : n connection, interrupts cannot be used.
RESET
disc
F1
F2
F3
F4
F5
F6
F7
SYSTEM
POWER
CN1
RS-232C or RS-422 (RS-485)
ZM-300 series
Write
General-purpose computer
Dedicated commands
Interrupt
Read
CN1 CN1 CN1 CN1
F1
F2
F3
F4
F5
F6
F7
SYSTEM
POWER
F1
F2
F3
F4
F5
F6
F7
SYSTEM
POWER
F1
F2
F3
F4
F5
F6
F7
SYSTEM
POWER
F1
F2
F3
F4
F5
F6
F7
SYSTEM
POWER
CN1 CN1 CN1 CN1
F1
F2
F3
F4
F5
F6
F7
SYSTEM
POWER
F1
F2
F3
F4
F5
F6
F7
SYSTEM
POWER
F1
F2
F3
F4
F5
F6
F7
SYSTEM
POWER
F1
F2
F3
F4
F5
F6
F7
SYSTEM
POWER
RS-42 (RS-485) connection
ZM-300 series No. 1
General-purpose
computer
ZM-300 series No. 2 ZM-300 series No. 3 ZM-300 series No. “n” (n = 1 to 32)