Bit Block Write
- CIMON (Unlicensed)
This function is to assign PLC device memory directly to write the bit block. The data can be assigned up to 16 pieces repeatedly.
But, The total sum of the word data is not to be over 256 bits.
Requested Format (PC -> PLC)
Bit Block Write (Master sends.)
Cmd – 77h
ID | Frame No. | Cmd | Res. | Length | Data | Check Sum |
ID : This is a 9-byte string like "KDT_PLC_M".
FrameNo : This, a 1-byte data with the range from 0 to 127, is the number of the frame controlled by Master party.
Cmd : 1 Byte, 77h(Bit Block Write)
Res : 1 byte of a reserved device (00h)
Length : Total number of the bytes of a frame data device
Data : (Ex.) ‘The case to write 4 bits as 1, 0, 0, 1 from Y0000D’
Offset(Byte) | Meaning of Data | Ex. | Remarks |
0 | Main Device Prefix (ASCII) | ‘Y’ | Assigns the ASCII Prefix of the bit device supported from a PLC. |
1 | Sub-Device Prefix or ‘0’ (ASCII) | ‘0’ | Sub-Prefix in case of the 2-character prefix device |
2 | Device Address (ASCII) | ‘0’ | The bit address of a corresponding device is used. |
3 | ‘0’ | ||
4 | ‘0’ | ||
5 | ‘0’ | ||
6 | ‘0’ | ||
7 | ‘D’ | ||
8 | Write Size (Bit) | 00h | Number of bits, Value in the range from 0001h to 0100h (1~256) |
9 | 04h | ||
10 | Bit Data | ‘1’ | Bit Value (ASCII, Set=’1’, Reset=’0’) |
11 | Bit Data | ‘0’ | Bit Value (ASCII, Set=’1’, Reset=’0’) |
12 | Bit Data | ‘0’ | Bit Value (ASCII, Set=’1’, Reset=’0’) |
13 | Bit Data | ‘1’ | Bit Value (ASCII, Set=’1’, Reset=’0’) |
Check Sum : This is 2-byte value. After the entire frame is binary-summed by the byte, the lower 2-byte in the result value is used.
Responded Format
ACK Response
This is the frame responding to ‘Bit Block Write’ that Master requests to write, in case of receiving Master’s request correctly and responding.
Cmd – 41h
Data Device
Offset(Byte) | Meaning of Data | Ex. | Remarks |
0 | Error Code | 00h | Error Code (Non Error Code) |
1 | 00h |
NACK Response
In case that the service to ‘Bit Block Write’ cannot be given due to error in a system or other reason,
Cmd – 41h
In the case of responding to Error Code (Refer to the Error Code table for the Exclusive Service.)
Data Device
Offset(Byte) | Meaning of Data | Ex. | Remarks |
0 | Error Code | 00h | Error Code (Error in Bit Write Data) |
1 | 0Dh |