User manual

TMCM-6110 TMCL Firmware V1.19 Manual (Rev. 1.03 / 2012-JUL-31) 14
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Checksum calculation
As mentioned above, the checksum is calculated by adding up all bytes (including the module address
byte) using 8-bit addition. Here are two examples to show how to do this:
 in C:
unsigned char i, Checksum;
unsigned char Command[9];
//Set the “Command” array to the desired command
Checksum = Command[0];
for(i=1; i<8; i++)
Checksum+=Command[i];
Command[8]=Checksum; //insert checksum as last byte of the command
//Now, send it to the module
5.2 Reply Format
Every time a command has been sent to a module, the module sends a reply.
The reply format for RS485/USB is as follows:
Bytes
Meaning
1
Reply address
1
Module address
1
Status (e.g. 100 means “no error”)
1
Command number
4
Value (MSB first!)
1
Checksum
 The checksum is also calculated by adding up all the other bytes using an 8-bit addition.
 When using CAN bus, the first byte (reply address) and the last byte (checksum) are left out.
 Do not send the next command before you have received the reply!
5.2.1 Status Codes
The reply contains a status code.
The status code can have one of the following values:
Code
Meaning
100
Successfully executed, no error
101
Command loaded into TMCL
program EEPROM
1
Wrong checksum
2
Invalid command
3
Wrong type
4
Invalid value
5
Configuration EEPROM locked
6
Command not available