I/O

[Guest Stef_pen]

1. In the c220he, the chassis has 8 slots/ racks, how does the plc know what is plugged in those slots/racks? 2. in writting a plc program, how do i determine wat address to use for accessing those input / output modules plugged into each slots/racks? 3. wer can i download manual for the following: a. ID215 b. ID217 c. OD215 d. ID212 e. od212 also , thanks alot jay, i already did wat u told me, i was able to make the cable and has succesfully communicated with the c220he

[Guest Gili]

Hi 1)I/O TABLE: The PLC have information of the cards connected to it stored in "PLC I/O table". This table "knows" what kind of cards are connected according to two methode: a) Automatic I/O table creation at startup. This technic is used for the small PLC's. At power up, the PLC serch the possible addresses and inquire the devices connected for their type. b) Manual I/O table creation with automatic verification at startup. This technic is used in the bigger PLC. After attaching cards to the PLC the user have to operate the I/O table icon, connect to the PLC, change it to program and select "Create". c) I know I said two but there is a third one. The "big" PLC's can identify and update this table automatically like the small PLC's with some of the simple cards. 2) I/O NUMBERING: After the I/O table is ready, The PLC numbers the found I/O's according to certain rulles. Most PLC's (like yours) assign consequtive numbers according to the position and type of devices. Your PLC set numbers for the left most card as 00. If it is discreat device then it's first input or output will be 00000 or 000.00, second is 00001/000.01 and so on. Second card will start at 00100/001.00 and so on. If a card is not I/O (communication card for example) then the address of it's position is skipped. If for example you install an output card at left position, second-communication,third-input, then the PLC outputs will be 000.00 to 000.15 and inputs 002.00 to 002.15. Some cards are "SPECIAL I/O UNITS" and they are numberd according to a switch position located at its front panel. Again, the original address of its location, is skipped. Gili

[Jay Anthony 118]

Thanks, Gili! All the information above is correct, but you also mentioned the ID217. This is a 4 channel (64 bit) DC input module and is part of the Group 2 I/O family. Because it has more inputs than the simple 16 bit input modules, it is addressed by the rotary selector switch found on the front of the module. If the number is 0, then the module wil be assigned to word 30-33. If the number is 1, then the module will be assigned to word 32-35. Hope this helps.

[Guest wolf]

Hi I’m just starting with Omron plc and trying to make the first plc program. About the PLC I/O table, witch plc have the automatic and manual I/O table creation at startup. I have a CJ1M and 2 I/O slots, ID211 and OC211. I supose that the addresses will be 00000..00015 and 00100..00115 like gili says. What happen if I mistake the I/O table? I also have a CPM2A, what is the I/O address for this PLC? Thanks

[Jay Anthony 118]

The CPM1A is not modular (modules on a rack or stack). Therefore it's I/O addresses are fixed from the factory. For the CPM1A, the input addresses start at 0000.00 and the output addresses start at 0010.00.

[Guest wolf]

Thanks Jay