OPERATION MANUAL CompoBus/S

CQM1-SRM21-V1 Master Unit for CQM1 PLCs Section 4-4
The group of words allocated to the Master is determined by the mounting
position of the Master Unit, and the specific bits used by each Slave are determined
by the node number set on the Slave.
Master Units for CQM1 PLCs don’t have the status area information that
is provided with the Master Units for CS-series,
C200HX/C200HG/C200HE-(Z)E, and C200HS PLCs.
The following equation shows the maximum time required for inputs from
the Input Slaves and outputs to the Output Slaves to become effective
after the CompoBus/S System is turned ON.
In High-speed Communications Mode: (PLC cycle time) + 118 ms
In Long-distance Communications Mode: (PLC cycle time) + 720 ms.
This delay must be taken into account when writing ladder programs for the
PLC. It is recommended to write a routine in the ladder program that checks
whether the alarm output terminal is OFF before processing I/O with the
Slaves.
Master Unit Settings The following settings affect I/O allocations to Slaves of the Master Units used
with CQM1 PLCs.
PLC Word Allocation
In order for the Master Unit to allocate words to Slaves, the total number of
words allocated to the Master Unit must be set in the PLC. The following three
settings can be made:
2 words (1 input word, 1 output word)
4 words (2 input words, 2 output words)
8 words (4 input words, 4 output words)
Number of Points/Node Number
This setting determines the amount of memory (number of bits) allocated to
each node number. The following two settings can be made:
8 points (8-point mode)
4 points (4-point mode)
Refer to the table on page 129 for details on the possible combinations of DIP
switch settings.
Slave Allocations The Slaves are allocated input and output words as shown below. In Compo-
Bus/S Systems, the node numbers of Input Slaves and Output Slaves are
handled separately so the same node numbers can be set for both one Input
and one Output Slave.
I/O Allocations in 8-point Mode
PLC Word Allocation: 2 Words
The following diagram shows the I/O allocations when the DIP switch is set as
shown below.
Pin 1: OFF Pin 2: OFF Pin 3: OFF
Inputs: First word
Input Slave 1
Input Slave 0
Outputs: First word Output Slave 1
Output Slave 0
PLC Word Allocation: 4 Words
The following diagram shows the I/O allocations when the DIP switch is set as
shown below.
Bits
131