Wednesday, July 13, 2011

Modifying the Configuration Parameters

According to the programming panel you are using, you can change a lot of the auto-configuration settings for a PLC. The HHP* permits you to modify only a few auto-configured parameters, while MODSOFT Lite offers you a great deal of elasticity in the configuration setting.

The References Number
You may be able to change the mix of references in your configuration with MODSOFT Lite. Nevertheless, you can’t enlarge the total count of register. For instance, if your application needs references for 32 more 0x, you can put in 32 to the existing total if you reduce the 1x references number by 32 or if you reduce the references number for 3x or 4x by 2 (3x and 4x registers include 16 bits; 0x and 1x references are single bits).

The Logic Segments Number
The value of auto-configured 2 should not be altered even if you do not plan to utilize subroutines. The second segment will never be examined except it is called by an instruction of JSR or by a hardwired break off.

Communication Parameters of RS-232 Port
The ports of RS-232 can be set to run in either of two modes— simple ASCII or Modbus. The port is a slave to the master device of Modbus that is linked to it, in Modbus mode; this device is usually a programming panel. The port is written or read with ladder logic in simple ASCII mode.

Modbus Mode
The port can correspond with either an 8-bit protocol of remote terminal unit (RTU) or a 7-bit protocol of ASCII in Modbus mode. ASCII can be supported only at 2400 baud and RTU can be supported only at 9600 baud on the comm 1 port of RS-232. The port of comm 1 is also controlled to Even parity and 1 STOP bit for ASCII and RTU. The port of Modbus address can be set in the range 1 ... 247.

Note, A Micro PLC can be a nodule on a network of Modbus by conveying it a unique network address of Modbus. If the PLC is not on a network of Modbus, the default address of 1 should be kept. If the PLC is on a network of Modbus, its address has to be unique with reverence to all other nodes on the network, in the range 1 ... 247. If your PLC has a comm 2 port of RS-232, there are more choices port parameters existing to you in mode of Modbus.

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