Embedded Systems LM5p-GSM, Product Manual

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61. -- request ok
62. else
63. -- reply with an error
64. if res [ 1 ]== nil then
65. return nil , res [ 2 ]
66. -- normal reply
67. else
68. return unpack ( res )
69. end
70. end
71. end
Handler (resident script with 0 delay) configuration
1.
mb:open()
Open Modbus TCP connection
2.
mb:setslave(10)
set slave device id
3.
mb:setmapping(10, 10, 10, 10)
set number coils, discrete inputs, holding registers and input registers
4.
mb:setwritecoilcb(function(coil, value)...
callback function which is executed for each coil write
5.
mb:setwriteregistercb(function(coil, value)...
callback function which is executed for each register write
Handler script example
1. -- modbus init
2. if not mb then
3. require ( 'luamodbus' )
4. mb = luamodbus.tcp ()
5. mb:open ()
6.
7. -- init slave storage for coils, discrete inputs, holding registers and input registers
8. mb:setmapping ( 10 , 10 , 10 , 10 )
9.
10. -- coil write callback
11. mb:setwritecoilcb ( function ( coil, value )
12. if coil == 0 then
13. grp. write ( '1/1/1' , value, dt.bool )
14. else
15. alert ( 'coil: %d = %s' , coil, tostring ( value ))