COTRUST CTH200 Series User Manual

Appendix
172
MagicWorks PLC or SETP7-Micro/WIN, FPORT communication. The MBUS_INIT controls Port
is set to Modbus is still PPI.
2) All SM corresponding to selected FPORT
3) Occupy 92 byte program space
※ Steps use Modbus slave station protocol in CTH200 program
1) MBUS_INIT can be used to initialize or modify Modbus communication parameters when there
are only one loop cycle. When you insert the MBUS_INIT, several hidden subroutines and
interrupt service routines are automatically added to your program.
2) Use only one MBUS_SLAVE instruction in your program. It execute in each cycle and serves
all requests received.
3) Connect CTH200CPU with Modbus master station by communication cable.
※ All functions the Modbus slave station protocol instruction support
Modbus slave protocol instruction supports Modbus RTU protocol. It uses the FPORT function of
S7--200, and supports most common Modbus functions. Support following Modbus functions:
Function
Description
1
Read single/multiple coil (actual output) status. 1 return any digital outputs
ON/OFF status(Q)
2
Read single/multiple contactor (actual input) states. 2 returns the on/off status
for any number of input points(I)
3
Read single/multiple hold registers. 3 returns the contents of V memory, keep
the register in Modbus as the word-type, and up to 120 words in a request.
4
Read single/multiple input registers. 4 returns simulated input values.
5
Write single coil (actual output). 5 sets the actual output point which is not
mandatory to the specified value. User program can override the values
written by the Modbus request.
6
Write a single hold register. 6 writes a single hold register value to the S7-200
V memory.
15
Write multiple coils (actual output). 15 writes multiple actual output values to
the Q image region of S7-200. The starting output point must be the
beginning of a byte (such as Q0.0 or Q2.0), and the number of outputs to
write is a multiple of 8. This is the limit of Modbus slave station protocol
instruction. These points are not mandatory, user program can override the
values written by the Modbus request.
16
Write multiple hold registers. 16 write multiple save registers to S7-200 V
zone. Up to 120 words can be written in a request.
※ MBUS_INIT instruction
The MBUS_INIT directive is used to enable and initialize or disable Modbus communication. The
MBUS_INIT directive must execute error-free before using the MBUS_SLAVE directive. Before
proceeding to the next instruction, the MBUS_INIT instruction must finish executing and set
Done bit immediately. The MBUS_INIT directive should be executed only once per
communication state change. Therefore, EN input should use edge detection elements to trigger

COTRUST CTH200 Series Specifications

General

Brand	COTRUST
Model	CTH200 Series
Category	Controller
Language	English