6. CONNECTION OF I/O UNITS TO
DO signal reaction to a system alarm
If a system alarm occurs in a Power Mate using the connector panel I/O
module, or if I/O Link communication between the Power Mate and
connector panel I/O module fails, all the DO signals of the I/O module are
turned off. Therefore, due care must be taken when setting up the machine
sequence. Also, the same phenomenon occurs if the power to the Power
Mate or the I/O module is turned off.
For the connector panel I/O module, I/O addresses are mapped as follows.
Xm+15 (DO alarm detection)
Xm+12 (for 1st MPG)
Xm+13 (for 2nd MPG)
Xm+14 (for 3rd MPG)
DI space map DO space map
The basic connector panel I/O module is allocated a group of DI addresses
(16 bytes) and a group of DO addresses (8 bytes). Up to three hardware
extension units can be added or removed as required. The reason for this
address allocation is explained below.
The MPG interface (MPG counter) occupies a DI space from Xm+12
through Xm+14. These addresses are fixed regardless of whether
extension unit 2 or 3 is used, and Xm+12 through Xm+14 must be
allocated as a DI work area to enable the use of the MPG. Therefore, when
using an MPG, allocate DI addresses in units of 16 bytes. Do not use the
DI space from Xm+12 through Xm+14 for Ladder; the Power Mate
processes the MPG counter value directly.
DI address Xm+15 is used for detecting overcurrent and overheating
alarms that occur in the IC used in the DO driver. [For details, see the
section describing the detection of DO (output signal) alarms.] This
address is fixed regardless of whether extension unit 2 or 3 is used, and
it must be allocated as a work area before it can be used. When using this
area, therefore, allocate DI addresses in units of 16 bytes.