Omron SYSMAC CV Series Operation Manual page 417

Special I/O Instructions
Precautions
1, 2, 3...
Flags
This instruction cannot be used to read data from Special I/O Units mounted to
Slave Racks in SYSMAC BUS Remote I/O Systems. It can be used for certain
Special I/O Units mounted to newer version of SYSMAC BUS/2 Remote I/O Sys-
tems. Refer to page 43 for details.
N must be BCD. (Special I/O Units can transfer up to 255 words of data.)
S must be in the I/O Area and allocated to a Special I/O Unit.
If the ER Flag (A50003) or CY Flag (A50004) is turned ON, the instruction will not
be executed.
If the data cannot be sent or the Special I/O Unit is busy, the data will be trans-
ferred during the next cycle. To make sure that READ(190) execution has been
completed, check EQ (A50006).
A maximum of two READ(190)/WRIT(191) instructions can be used for Slaves
connected to the same Master. If a third instruction is attempted when two
instructions are already being executed, the third instruction will not be executed
and the Carry Flag (A50004) will turn ON. Be sure to control execution of these
instructions so that no more than two are being executed simultaneously for
Units connected under the same Master.
This instruction cannot be used to read data from Special I/O Units mounted to
Slave Racks in SYSMAC BUS Remote I/O Systems. It can be used for Units
mounted to Slave Racks in SYSMAC BUS/2 Systems as long as the the follow-
ing conditions are met.
1. The lot number of the Remote I/O Master Unit and Remote I/O Slave Unit
must be the same as or latter than the following.
01
2. The DIP switch on the Remote I/O Slave Unit must be set to "54MH." (Only
four Slaves can be connected to each Master when this setting is used.)
3. The Special I/O Unit must be one of the following: AD101, CT012, CT041,
ASC04, IDS01-V1, IDS02, IDS21, IDS22, LDP01-V1, or NC222.
4. No more than one READ(190) and/or WRIT(191) cannot be executed for
the same Special I/O Unit at the same time. Be sure the first instruction has
completed
READ(190)/WRIT(191) instruction.
Note Refer to page 115 for general precautions on operand data areas.
Content of *DM word is not BCD when set for BCD.
ER (A50003):
S is not allocated to a Special I/O Unit.
N is not BCD.
Instruction executed reading more than 255 words from a
Special I/O Unit on a SYSMAC BUS/2 Slave Rack.
The Slave is not set to 54MH.
CY (A50004): This Flag operates only for Special I/O Units mounted to
SYSMAC BUS/2 Slave Racks and turns on for the following:
The Special I/O Unit or Slave is busy.
An error has occurred in the Special I/O Unit.
Word operands have been designated for a Special I/O Unit
that requires a constant.
The communications path is not normal.
EQ (A50006): OFF while data is being read; ON when reading has been
completed.
X 2
1992
October (Y: November; Z: December)
1st
execution before starting
Section 5-35
execution of another
405