I/O Expansion Specifications - FATEK M Series User Manual

The expansion of M-series PLC means when the resources provided by the M-series CPU module are
insufficient or the interface not provided by the CPU module. The number of I/O or interface types can be
expanded by adding expansion modules. The expansion of M series PLC can be divided into two categories:
I/O expansion and communication port expansion.

2-1 I/O Expansion Specifications

The expansion of M Series PLC I/O consists of Digital I/O (DI/O, which status is represented by a single
bit) and the Numeric I/O (NI/O, which status is represented by a 16-bit Word). Either the DI/O or the NI/O
expansion is realized through expansion modules cascaded thru the usage of the "I/O Output Expansion
Connector" located at the right side of M Series PLC or expansion module.
The I/O points of M-Series PLC are limited to 2048 points of DI/O (1024 points each for DI and DO),512
words of NI/O (256 points each for NI and NO). Hardware limitations: ①. A maximum number of 64
modules can be used in the expansion. ②The number of expansion modules that can be connected in
series in each segment of the M-series PLC is limited to 16 units, and expansion modules or branch modules
must be used for extension between each segment.
1. If the I/O points of the application system exceed one of the limitations (1024 DI,1024 DO,256 NI,
256 NO), while startup the M-Series PLC will treat this as an illegal I/O configuration, which in return
will flag as an error situation by turn on the "ERR" LED. The corresponding error code will also be
indicated in the CPU status register (DR35361).
2. The maximum number of expansion modules of M-Series PLC is 64. Beyond this numbers will be
treated as an invalid I/O configuration and the CPU Module will stop its operation, which in return
will flag as an error situation by turn on the "ERR" LED. The corresponding error code will also be
indicated in the CPU status register (DR35361).
3. The number of expansion modules that can be connected in series in each segment of the M-series
PLC is limited to 16 units, and expansion modules or branch modules must be used for extension
between each segment.
1. The maximum length of the I/O expansion cable for M-Series PLC is @5 meters. Cables longer than
that will cause incorrect I/O operation because of excess signal delay in hardware or noise pickup,
resulting in damage to equipment or posing hazard to operating personnel. Since this kind of
situation cannot be detected by the CPU Module, users are advised to take extra cautions and
necessary measures.
Chapter 2 Expansion of M-Series PLC
Caution
Warning
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M-Series PLC Expansion Module User Manual