Micromod Micro-DCI: 53SL5100A Single Loop Controller - Manual (Page 140)

Single Loop Process Controller Instruction Manual
132 Communications
B.1.6 Software Characteristics
1. Transparency Rule - whenever 7E hexadecimal is transmitted as anything other than SOH, a
00 byte will be inserted directly following it (byte stuffing).
2. All transactions are initiated by the Host or SUPERVISOR-PC.
3. All instruments begin their response within 10 ms after the end of the transmission by the Host
or SUPERVISOR-PC; otherwise, a faulty transmission may be assumed.
4. Illegal messages received by the instruments are ignored.
5. The host must acknowledge the instrument’s response to a CHANGE REQUEST within 100
ms or the request is ignored.
6. A break of 100 ms in a message causes the instrument to ignore the part of the message
before the break.
7. The maximum number of data bytes per message is 32 (decimal).
B.1.7 Hardware Characteristics
1. Transmission Speed - standard rates are 300 - 28800 baud.
2. Asynchronous by character.
3. A character is:
1 Start bit.
8 Data bits - the Least Significant Bit (LSB) is transmitted first.
1 Even Parity bit.
1 Stop bit.
4. Line is 4-wire, shielded twisted pair, type RS-422/485.